A NEI'J FLAME I

A NEI'J FLAME I<ETARJJA:JT SYSTEM FOP. COTiON

ArTO POLYESTER COTTON' BLEN-DS

A TFJISIS

Presented to

The Faculty of the Division of Graduate

Studies and Research

By

Felix Serret

In Partial Fulfillment

cf the Requirements for the Degree

Master of Science in the School of Textile En{?,iaeering

Georgia Institute of Technology

December, 1971

( HT-

A NEW FLAME RETARDANT SYSTEM FOR COTTON

AND POLYESTER COTTON BLENDS

Approved:

Chairman /

Date approved by Chairman:_

ii

ACKI^OWLEDGMENTS

I would like to express ray sincere appreciation to my thesis

advisor, Dr. Wayne Tincher, for his enthusiastic and valuable

guidance in this thesis research work.

Appreciation is also expressed to Dr. Walter C. Carter and

Dr. Wolfgang Wulff for their service on the reading coiiimittee.

Ill

TABLE OF CONTENTS

Page

ACKNOIVLEDGMEMTS ii

LIST OF TABLES v

LIST OF ILLUSTRATIONS vi

SUMMARY viii

CHAPTER

I. INTRODUCTION I

Role of the Textile Materials in Burn Injuries and Deaths History of Legislation Need for Further Research

II. CURRENT STATUS OF FLAME RETARDANCY OF TEXTILE MATERIALS .. 5

Mechanisms of Thermal Degradation of Cotton and Polyester Fibers

Approaches to Improvement of Flame Retardancy of Cellulose Materials in Common Use as Flame Retardants Requirements for Flame Retardants for Textile Material Present Status of Flame Retardant Treatments for Cotton

and Cotton Blend Fabrics Phosphorous Nitrogen Compounds Treatments Based on Tetrakis (Hydroxyroethyl) Phosphonium

Chloride and Its Derivatives Treatments Based on Phosphorous-Halogen Compositions Problems With Current Treatments The Approach Taken in the Current Work

III. EXPERII^NTAL PROCEDURES 34

Materials Selected for Study Formulation of the Flame Retardant Emulsion Application of the Flame Retardant System Reference Samples Testing

Flammability Tester Durability Color Hand Tensile Strength Wrinkle Recovery Test

IV

TABLE OF CONTENTS (Cont'd)

Page

CHAPTER

IV. RESULTS AND DISCUSSION 44

Results of Flammability Tests Results of Color Measurements Evaluation of Fabric Hand Fabric Tensile Strength Wrinkle Recovery Results Conclusion and Recoiranendation

APPENDIX 53

BIBLIOGRAPHY' 73

LIST OF TABLES

Table Page

1. Pyrolysis of Cellulose in a Vacuum 8

2. The Gaseous Products of Decomposition of Polyester at Low Temperatures (280°C to 320°C) 10

3. Minimum Addition of Inorganic Halides Required to Reduce Char Length Below 10 Inches in the Test in Which the Sample Kept the Vertical Position 15

4. Inorganic Halides with Suggested Fire Retardant Applications 16

5. Some Organo-Bromo-Chloro Compounds Which Have Been Investigated as Flamc-Retardants 18

6. Ion Exchange Reactions of Cellulose-Phosphace Treatment and Their Effect on Flc.mci Resistance 21

7. Amount of Phosphorous Material to Render Cellulose Nonflammable 24

8. The Effect of Ammonium Dihydrogen Phosphate Retardant System on the Amount of Dry Gas Produced During the Pyrolysis of Cotton Fabrics 26

9. Chemical and Physical Characteristics of the Tris(2,3-Dibromopropyl) Phosphate 35

10. Properties of Triton X-45 and X-100 Emulsifying Agents with Non-Ionic Character 36

11. Chem.ical and Physical Characteristics of Seycorez C-13 and Acryloid B-82 38

12. Comparative Flaminability Results With the Different Formulations 48

13. Comparative Color Results (Yellowness Index) with the Different Formulations 49

14. Comparative Hand Results with Different Formulations . 50

15. Comparative Strength of Treated and Control Samples: Results in Per Cent Strength Retention 51

vi

LIST OF TABLES (Cont'd)

Table Page

16. Comparative Wrinkle Recovery in Degrees with Different Treatments 52

vii

LIST OF ILLUSTRATIONS

Figure Page

1. Flammability Test on Cotton Samples Treated with Formulation Based on Phosphoric Acid 64

2. Flammability Test on Cotton Twill Samples Treated with Formulation Based on Di-Ammonium Phosphate, Urea and Boric Acid 65

3. Flammability Test on Cotton Twill Samples Treated with Formulation Based on THPC 66

4. Flammability Test on 65/35 Polyester/Cotton Blend Treated with Formulation Based on THPC 67

5. Flammability Test on Polyester/Cotton Blend Samples Treated with Formulation Based on Tris-2,3 DBP 68

6. Flamraability Test on Cotton Ti ill Samples Treated with Formulation Based on Tris-2,3 DBP with Acrylics 69

7. Flammability Test on 65/35 Polyester/Cotton Blend Samples Treated with Formulation Based on Tris-2,3 DBP with Acrylics 70

viii

SUMMARY

The textile industry faces severe problems in meeting new

requirements for flame retardancy of textile materials. All durable

flame retardancy treatments available at the present time rely on

reaction of the active component with the cellulose in cotton or

cotton blend fabrics. These reactions have undesirable side effects

in that they significantly reduce fabric strength and increase fabric

stiffness.

A new flame retardancy treatment has been developed which is

durable through 10 launderings and which is not reactive with the

cellulose substrate. The active ingredient in this formulation is

tris(2,3 dibromopropyl)phosphate. A standard fabric finish based

on poly(acrylic acid) polymers is used to entrap the active ingre

dient and improve the durability of the flam.e retardancy treatment.

This new formulation can be prepared as a water based emulsion and

can be applied to fabric on standard commercial fabric treatment

machinery. The cost of this new flame retardancy treatment is in

the range commercially acceptable for fabric treatment processes.

Comparison of the properties of fabrics treated in this way

with fabrics treated by conventional flame retardancy processes

shows that treatm.ents based on tris (2,3-dibromopropyl)phosphate

give significantly improved tensile strength and wrinkle recovery

to the treated fabric. Other physical properties are comparable

with those resulting from the various treatment systems.

IX

Improvements in the hand and color of fabrics treated with

tris(2,3-dibromppropyl)phosphate should make available to the textile

industry a new flame retardancy treatment which can be applied to a

broad range of textile products and, thus, contribute significantly

to reduction in burn injuries and deaths that result from the flamma-

bility of textile materials.

CHAPTER I

INTRODUCTION

Role of Textile Materials in Burn Injiiries and Deaths

Approximately two million burn accidents occur in the United

States each year. Of the people involved in these accidents about

75,000 require hospitalization and 9,000 ultimately die as a result

of burn injuries. These statistics place burn accidents as the third

largest cause of accidental deaths in the United States (1). Statistics

compiled by the Department of Health, Education, and Welfare suggest

that 3,000 to 5,000 of these deaths result from burns associated with

flammable fabrics. Flammable fabrics are also responsible for approxi

mately 200,000 non-fatal injuries and a financial loss exceeding a

quarter of a billion dollars annually (2). A recent study by McDonald

(3) reported that textile products were the primary agent involved in

33 percent of the burn cases investigated. Of the textile related

fires, 71 percent involved household textile products and 29 percent

apparel textile products. Similar results were obtained in a recent

study of 4,900 burn cases by the National Bureau of Standards.

Approximately 1,200 of the cases investigated were caused by fabric

ignition. An in depth study of 359 of the fabric related burn cases

revealed that 239 resulted from the burning of sheets, blankets and

bedspreads. The remaining 320 burn injuries were related to apparel

fabrics with nightwear and underwear responsible for the majority of

the burn injuries (4).

These statistics clearly indicate the need both for more

information on the role of textile materials in injuries and deaths

resulting from burn accidents and on means for reducing the hazards

associated with these materials. A recognition of these needs by

governmental agencies has led to increasing interest on the part of

government in controlling the manufacture and sale of hazardous

textile products (5).

History of Legislation

The first federal legislation relating to the burning of

textile materials was the Flammable Fabric Act of 1953. This legis

lation was enacted as a result of several deaths from the burning of

sweaters and negligees constructed of a highly flammable cellulosic

material. The law prohibits the marketing of highly flammable

textile materials and sets standards to be applied in the testing

of textiles for flammability (2). This act was intended to prohibit

marketing of only the most hazardous materials. It does not apply

to blankets, bedspreads, toys, or household textiles (5).

Due to the limitations of the Flammable Fabric Act of 1953,

Congress amended this act in December of 1967 to give the Department

of Commerce the authority to revise and strengthen the current

standards and to set new standards where they were needed. The new

law not only covers textile materials but also paper, plastics,

rubber, foam, and interior furnishings as well as hats, gloves,

and interlining fabrics (2). The first action taken by the Secre

tary of Commerce under the amended Flammable Fabric Act has been the

establishment of flammability standards for children's sleepwear.

This initial action was followed by new standards for rugs and carpets

Standards for many other textile materials will undoubtedly follow

in the next few years (2).

Need for Further Research

Following the notice that there may be a need for new or

amended standards for the flammability of wearing apparel, consi

derable effort by mills, schools, and laboratories has been given to

evaluation of existing test methods and to the development of new

tests for establishing the flammability of textile products. At

the same time, many chemical producers are investigating new ways

to treat fabrics to improve flame retardancy characteristics.

Fabric flammability is undoubtedly the most important area of

research currently under investigation in the textile industry.

The major emphasis of research work at the present time is

on development of chemical treatments to improve the flame retardancy

of cotton and cotton blend fabrics. The synthetic fibers are flam

mable (6) buc the burning characteristics can be greatly modified

by the fiber manufacturer through changes in the chemical structure

of the polymer (7) or by incorporation of flame retardants in the

fiber during manufacture. The flammability of cotton, on the other

hand, can only be altered by treatments applied to the fiber or to

fabrics. The current work, therefore, has been directed tov7ard

treatments which can be applied to cotton or cotton-polyester blend

fabrics.

Previously developed chemical treatments for improving the

flame retardancy of textile materials containing cotton all -rely on

chemical reaction of the flame retardant materials with the cellulose

substrate to achieve durability. Loss of tensile strength of the

fabric and reduction in desirable aesthetic properties has inevitably

resulted (8). In view of the increased importance of flame retardancy

and the limitations of current flame retardant treatments, the present

work was undertaken to determine if a durable flame retardant system

could be developed which does not have the disadvantages of present

systems.

CHAPTER II

CURRENT STATUS OF FLAME RETARDANCY OF TEXTILE MATERIALS

Mechanism of Thermal Degradation of Cotton and Polyester Fibers

Cotton is a naturally occurring fiber composed primarily of

cellulose, (C^H^-O^) , a polysaccharide of beta-glucose units linked o lU 3 n

together through the 1 and 4 positions by formation of acetal groups

cK^^oH

1/" oH H / M

CH

oH

r

cHj^O+i

iO«

The three hydroxyl groups in each repeating unit provide opportunity

for strong hydrogen bonds between the cellulose chains. These pendant

hydroxyl groups are also responsible for many of the chemical reactions

of cellulose. The acetal linkages are subject to chemical attack and

scission of these linkages results in lowering of the molecular weight

and loss of fiber tensile strength. Cellulose burns freely in air

with a luminous, smokeless flame similar to that of other alkanes (9-12)

The burning of organic materials is a complex process involving

a large number of successive steps of disintegration and oxidation.

The final products lend little information about the intermediate

states or mechanisms of the chemical reactions leading to the final

products CO^ and H2O (13).

For the purposes of the present discussion, the mechanism of

burning of textile materials may be divided into four stages - initial

heating, pyrolysis, gas phase reactions, and char formation. Each of

these stages is discussed below (14).

(1). Initial Keating: An external heat source supplies heat

to the fabric causing an increase in temperature. The increase in

thermal energy of the system depends on the size and temperature of

the heat source and on the physical properties (heat capacity, con

ductance, etc.) of the fabric. Fabric construction can have a signi

ficant influence on this stage. During this stage thermoplastic fibers

soften, melt, and begin to flow. In general this is the simplest

stage of the burning process.

(2). Pyrolysis: During this stage chemical decomposition of

fibers occurs with elimination of volatile gases and polymer fragments.

The rate of decomposition depends on the thermal stability of the

polymer. These decomposition reactions are very complex and not v/ell

understood (15).

(3). Gas Phase Reactions: The volatile gases resulting from

pyrolysis react with oxygen in the air and, under the appropriate

conditions, burn with emission of heat and light. If the oxidation

of the gases is sufficiently vigorous, enough heat is liberated to

carry out the pyrolysis of stage two and the external heat source is

no longer necessary to continue the process. Under these conditions

the flame is self propagating. If decomposition of the fabric requires

more heat than is supplied by burning of the gaseous products, a

continuous, propagating flame will not be obtained. •

(4). Char Formation: Non-volatile fragments resulting from

the pyrolysis step also undergo reaction in the tarry or solid residue.

These reactions in some cases produce a carbonaceous char which can

coat the surface of the fabric and insulate the remainder of the

flammable composition from the heat source. The residue may in this

way prevent flame propagation. The char itself can also undergo

oxidation even after the flame is extinguished and this reaction

is responsible for the phenomenena known as "after glow."

The mechanism of the thermal degradation of cellulose has been

investigated by a large number of workers. Although there is no

consensus as to the degradation mechanism two reactions are generally

considered to be important in the degradation. The first of these

is the dehydration reaction of hydroxyl groups and leads to cross-

linking of the cellulose structure. This cross-linking reaction

gives a high yield of char and probably retards the formation of

gaseous products. The second important reaction is the scission of

carbon-oxygen bonds in the backbone of the cellulose chain. If the

C-0 bond of the glucose ring is ruptured, complete breakdown of the

molecule results giving CO^, CO, and H^O. This reaction leads to

formation of large quantities of volatile products. An analysis

of the volatile products from degradation of cellulose has been

carried out by Madorsky (16) and is shown in Table 1. Scission

of the other carbon oxygen bond, the C-0 link between the glucose

units, leads to levoglucosan which appears to be stable thermally.

Mass spectrom.eter analysis of the tars from cellulose degradation

suggest that levoglucosan is a principal component of the tarry

6 =1 D O oj >

0)

o

TO • H CO

iH O M

oj H

Trl o Q; CTV-^ N — t o

•ri l O r H *— • H > 4-J cd

r H O

> r H cd i J o . ^ o 0 0 CN + j ex l O

0) u m i j > ^ o w e^

o « m

:y]

C •• o i j L O z - N •ri u CN O i-) cd o g

u CL > ;=:J cd - M

m Q;

T H

• H • u M . ^ cd >^ >

ex cd

QJ

& 1 > d • H

«> c i J

d d Cd

o CJ T H

• H •U d cd o N i j

• H i j r H o • H u 4.J cd ex.

T H M 0)

o O 4-»

> p>4 CO

a 1 > • H D • H

e e 4-» 3 Cd

«> U t H

d o

• H 4-1 cd a >-l u 

Q UA cn

4J a rC E GO cd w )

• H en E o CN

r^ v t CN —(

00 CO r^

i—( CN r-H

o in o <t • r^ • m 0-) CN

CN o ^ in • ^r • LO V t ^

(T> r~. • — ( vO • vO • ON CN LO

CO o i n

o rn CN

• ro • CN

• • — (

• CN CO CN

CN CN

r o a> C7 00

»vO r o m r o • O CN CO i n vo • r^

O LO CT> r^ vTJ vo

r^ r o r o v t o - ) - — t c o > s O O - « d -

CN r O O O N L ' - ^ L O — l O N C N - — I < — i ^ H O - ) < r v O v X > C N C T »

r^ o o O ' - H O N C O r ^ o o o ^ r

CN r o r ^ C 7 v u - i ( ^ o r ^ c g . — I ^H ^H CN CT»

O 0 0 v O c 7 ^ a ^ v D ' ^ I — t C T i C T v O f o a N < r < r c ^ ! O v o m CO —( CN CO m v o •—I

O o o o o f O O r ^ O L O a N C T i O c o m m o r ^ c x ^ L O m r O ^H ^H r—I I—I

.—1 f O f O c O c O C O f O f O L O O O

0\ r o c o c o c o c O c o c o c T v c o <3- O O O O O O O O C O C O C O C O ' — f

O O O O O O O O — t r ^ LO c x ) o o c x ) o o c o o o c o c N c r i CN c N C N c N C N c N C N c N r o r o

residue. Thus, materials which promote either dehydration or forma

tion of levoglucosan should improve the flame retardancy of cellulose

The structure of polyethelene terephthalate, the other fiber

forming polymer of interest in the current work, is shown below:

f C H x < ^ H z O C O — / \ _ ^ C O O - ^

In an attempt to elucidate the thermal degradation mechanism

of polyet-.helene terephthalate Goodings and Richey (17) have studied

decomposition of model compounds such as ethelene dibensoate. The

investigations show that the major reaction is ester decomposition

which leads to rupture of the polymer backbone with production of

carboxyl and vinyl end groups.

vyv/ Cc H4 COO-CM2,-CH2.- O C O C ^ ^^ ^^y^ - ^

'v^Cft H4—COOK -+ CH;2_=^ CH-OCOQH4^—^

The gaseous products- produced by low temperature (280 to 320 C)

pyrolysis of polyesters are given in Table 2 (18). As can be seen,

acetaldehyde is the major product of the low temperature decomposition,

The nongaseous products of the low temperature decomposition are

terephthalic acid and a substance of much more complex structure.

Decomposition of polyesters at higher temperature (340 - 475 C)

yields different products. Acetophenone and p-acetyl benzorie acid

10

Table 2. The Gaseous Products of Decomposition of Polyester at Low Temperatures (280°C to 320°C) (18)

Product Mole Fraction

CO 8.0

CO2 8.7

H2O 0.8

CH3CHO 80.0

C2H^ 2.0

2-Methyl Dioxolan 0.4

CH/. 0.4

Co»6 O'"

IL

are prominent among the gaseous products of this high temperature

decomposition (19). Thus, a quite different mechanism is apparently

active at the higher temperature.

Marshall and Todd (20) have measured the activation energy

for polyethelene terephthalate decomposition and report a value of

32 kilocalories/mole.

Considerably more research is needed on the thermal degrada

tion of polymeric materials, particularly in the presence of limited

amounts of oxygen. Such information would be extremely valuable in

attempts to find better flame retardant treatments for textile fabrics.

Approaches to Improvement of Flame Retardancy of Cellulose

The theory of fire retardancy in general is in a primitive

stage of development. Because of the complexity of the burning pro-

cesc, most of the theories are empirical. The nature of the polymer,

impurities or foreign material present in the polymer, melting

behavior of fibers or fabrics, soluble or insoluble additives present

in the system, are only a few of the many variables that must be

considered (21). However, based on the burning mechanism discussed

above and the information available on decomposition of cellulose

and polyester, it is possible to suggest certain approaches to

improving flame retardancy of textiles containing these materials.

(1). Cross-linking of Fiber Substrates: One important means

of improving the flame retardancy of cellulosic materials is to reduce

the quantity of volatile gases formed during pyrolysis. This can be

achieved by cross-linking of the cellulose substrate. Strong

dehydrating agents are useful in promoting reaction between hydroxyl

12

groups to give interchain bonding. Sulphates, phosphates, sulfamates

and other chemical groups are capable of forming interchain links in

cellulosic materials (22). With a high degree of cross-linking,

thermally induced chain scission leads to production of higher

molecular weight fragments which are retained in the solid state

even at high temperature. The ideal situation would be to retain

all of the carbon in the solid state leaving no oxidizable fragments

in the gaseous phase.

(2). Alteration of Gas Phase Reactions: Gas phase reactions

may be altered in two ways. First the textile material can be

treated with a flame retardant which will decompose at high

temperature with the production of nonoxidizable gases. These

gases dilute or exclude oxygen from the environment and prevent

the exothermic oxidizing reactions necessary for propagation of

the flame. Gases which may act in this way are CO2, NH^, HCl, H2O,

SO/j} Br«, and CI. Materials which might be added to textile products

to produce such gases would include sodium carbonate, sodium bicar

bonate, ammonium halides, and highly hydrated salts such as aluminum

sulphate (23).

The gas phase reactions may also be altered by the addition of

materials which readily generate free radicals on heating. These

radicals can react with radicals from the textile materials in the

flame and thus terminate the chain reactions responsible for much

of the heat generated by the flame. Thus, the energy source is

eliminated and the pyrolysis reactions necessary for maintaining

the burning cannot occur. It has been suggested that halogen

containing compounds improve the flame retardancy of polymeric

materials.

(3). Energy Absorption: Materials can be added to the

substrate which absorb energy by fusion, sublimation, or decompo

sition. These endothermic chemical and physical changes rob the

substrate of the energy necessary for pyrolysis and volatilization

of the products needed to maintain combustion. It has been shovm

that a 1:1 mixture of borax and boric acid can lower the temperature

of a burning fabric enough to prevent further flame propagation.

A similar effect can be achieved by altering the reaction

mechanism. For example, the production of one mole of CO^ yields

94.4 kilocalories of heat. Combustion of the same quantity of

carbon to produce carbon monoxide yields only 26.4 kilocalories.

Thus a significant reduction in the available thermal energy can

be achieved if the ratio of CO to C0« produced is increased. It

is believed that certain glow-proofing agents may act in this way (24)

(4). Substrate Coating: Many inorganic salts which improve

flame retardancy of textile materials fuse on heating to give a

glassy surface or film on the substrate. This barrier retards

flame propagation by two mechanisms. First it reduces the transfer

of thermal energy from the flame to the substrate and thus reduces

the pyrolysis reactions. It also prevents the release of volatile

fragments from the fabric surface and robs the flame of needed fuel.

The formation of a heavy char layer quite probably acts in the same

way in reducing flammability (25).

14

Materials in Common Use as Flame Retardants

The chemistry of fire retardance is centered around six

elements - phosphorus, antimony, chlorine, bromine, boron, and

nitrogen. Of the six, phosphorus and the halogens have achieved

the widest use in flame retardant treatments of textile materials.

Compounds of the above elements are often used in combination in

order to achieve the desired level of flame retardancy.

(a). The Halogens

The relative effectiveness of the halogens in imparting flame

retardancy to cotton twills is shown in Table 3. These data suggest

that iodine is most effective in improving flam.e resistance charac

teristics of textile materials with bromine second and chlorine

third. Fluorine in the form of inorganic halide is not very

effective in this application (26). Despite its effectiveness,

iodine is not widely used in flame retardant treatments, primarily

because of its high cost and low chemical stability. Both organic

and inorganic compounds of chlorine and bromine have been used in

many formulations for imparting flame retardancy to materials.

Some typical inorganic halides with suggested fire retardant

applications are given in Table 4 (27). Chlorine and bromine

containing compounds have long been used in flame retardant treat

ments for textile materials. Chlorinated paraffin, for example, was

used for many years in the preparation of heavy cotton fabrics for

tentage applications. Vinyl chloride and to some extent vinyl bromide

are co-polymerized v;ith other monomers in the preparation of flame

retardant plastics and textile fabrics. A partial list of the chlorine

15

Table 3. Minimum Addition of Inorganic Halides Required to Reduce Char Length Below 10 Inches in the Test in Which the Sample Kept the Vertical Position (26).

Addition Required % of Fabric Weight

Compound F CI Br

NH4"

L i +

Mg2 +

Zn2 +

24 5-6 4-7

30 6-7 5-6 4-5

40 7-9 3-4 5-7

14-17 5-6 7-8

Table 4. Inorganic Halides with Suggested Fire Retardant Applications (27)

16

Compound A p p l i c a t i o n

ZnCl,

MgCl,

MgBr,

B r " , BrOo" t o g e t h e r

ZnBr

T iOCl^ T i C i ^

NK^Br

Wood T r e a t i n g

C e l l u l o s i c D e r i v a t i v e s

T e x t i l e s

Polystyrene

17

and bromine containing compounds used as fire retardants in the

textile field is given in Table 5 (28, 29).

Chlorine and bromine apparently act in the gas phase to reduce

the flammability of materials. The inorganic or organic additive at

combustion temperatures decomposes to give chlorine and bromine vapors

which dilute the oxygen in the atmosphere adjacent to the combustible

material. The dissociated atoms also serve as free radical scavengers

to terminate the chain reaction mechanisms involved in the combustion

phase.

(b). Antimony Compounds

Antimony is very effective as a flam.e retardant when used in

conjunction with halogen containing ccmpounds (30). The discovery

of the antimony-halogen synergisim in reducing flammability has led

to much research on this system and a very extensive patent lite.ra-

ture (31). A formulation containing antimony oxide and chlorinated

hydrocarbons is the only presently acceptable method for producing

military fabrics (such as tentage, tarpaulins, etc.) with the

required durability to washing and weather (32). The synergistism

between antimony oxide and chlorine containing hydrocarbons is

undoubtedly due to the ability of the oxide to react with HCl to

give antimony SbOCl which on heating can yield antimony trichloride

Sb^O^ + HCl — ^ SbOCl — > SbCl^ (33).

Both the antimony and antimony trichloride are relatively volatile

compounds and probably increase the activity of the halogen atoms

in the gas phase reactions.

18

Table 5 . Some Organo-Bromo-Chloro Compounds IiHiich Have Been I n v e s t i g a t e d as Flame-Retardants (28 ,29) .

Bromocycloalkanes Tetrabromododecene Brominated P e n t a e r y t h r i t o l 2 ,2 Bis (bromomethyl ) - l ,3 Propanediol Dib*:omosuccinic Acid Broiaophynyl Vinyl Ether Bromophenol Tetrabromophthalic Acid Bromophthalimide

Polyvinyl Chloride Chloroethylenes Vinyl Chloride Chloroadipic Acid Vinyl Chloroacetate Chlorophenols Chlorinated 1, 4-bis-hydroKytnethyl Benzene

Chlorophenyl Isocyanate Chlorobiphenyls and Chloropolyphenols Chlorinated Naphthalenes Tetrachlorophthalic Acid

19

(c). Boron Compound

The element boron itself is not a good flame retardant but

many of its compounds such as borax and boric acid are good flame

retardants. These boron containing compounds are especially

effective when used in combination with inorganic m.aterials such

as sodium phosphate or organic compounds like glycerine (34). In

general, the retardants in this group consist of salts or mixtures

of salts V7hich when heated, melt at low temperature and then

resolidify in trie form of a solid foam. The solid foam is very

theriTially stable and probably consists of mixed compounds of

B 0„ with sodium and potassium oxide. These materials have melting

points approaching 1,000 C. They coat the surface of the burning

material to prevent further gasification of the pyrolysis products

and to serve as an insulation barrier to transfer of heat from the

flame to the substrate (35).

(d). Phosphorus Compounds

Phosphorus compounds are among the most effective and the

most widely used materials for improving flame retardancy of textiles

Both organic and inorganic phosphorus compounds are used and probably

act by cross-linking the cellulose structure as indicated in the

reaction below:

•20

no I CH

HO-C

H~C

-^ W3PO.

-oM H C~cHjpH

cH t

HO ( CH

MO-CZ-H

M-t. -OH H c-cH3_opoU ^M^o 2.^2.

crt (

Alr.hough this reaction with H^PO, yields a product which is not

flammable, it is of no use in practical work because of the severe

loss in mechanical strength of the cellulose structure. Careful

selection of the phosphorous compound is therefore extremely

important in producing the right properties in the finished

product (36, 3 7 ) . The addition of nitrogen containing compounds

which can essentially co-polymerize with the phosphorous compcunds

in forming the cross-links to yield longer chains between the

cellulose molecules are capable of reducing the brittleness and

therefore improving mechanical properties of flame retardant

treated textile materials.

One further disadvantage of phosphorous containing fire

retardants is that their effectiveness is reduced by normal washing

of textile materials, particularly if hard water is used. This

effect has been attributed by some workers (38, 39) to "ion exchange

reactions" of cellulose phosphate units in which calcium ions are

picked up from the wash water. The loss in effectiveness of the

calcium containing compounds has been demonstrated by Ward and is

shown in Table 6. It has been suggested that the calcium salts do

not decompose on heating to yield H_PO,, the active species in

21

Table 6. Ion Exchange Reactions of Cellulose-Phosphate Treatment and Their Effect on Flame Resistance (38).

Structure Reagent Product

Seconds After Flamming

45° Angle Test

Cell-OH None Cellulose 40

Cell-0^ Oli-NHo, ^ " \. ^P C = 0 0 ^0H-NK2^

Urea, Urea cellulose phosphoric phosphate acid

Cell-0 0 )? Ca

(f' \' CaCl, Calcium cellulose phosphate 25

Cell-0 ^OH"NH2

A 0 ^0H-NH2

NH^Cl

Diamonomium cellulose phosphate

Cell-0, 0 /P Ca

0 ^ \ CaCl. Calcium cellulose phosphate 32

Cell-0 OH

A 0 OH

CH^COOH Cellulose acid phosphate 3

22

in preventing thermal breakdown of cellulose. Despite these limita

tions, phosphorous compounds are among the most effective flame

retardants for textile materials and are therefore among the more

interesting materials for further research.

Requirements for Flame Retardants for Textile Material

Improving the flame retardancy of textile materials provides

an extremely challenging problem due to the great diversity of these

materials. Fabrics are constructed from a brjad range of fiber

types including cotton, wool, polyester, acrylics, nylon, poly-

olefins, etc. used both alone and in blends. These fibers of differing

chemical structure are assembled in many ways to produce fabrics

with a wide range of weights and styles. It is very unlikely,

therefore, that any one treatment will be applicable to all textile

materials. Some general requirements for "ideal" treatments for

flame retardancy of textiles have been suggested (40) and are

listed below:

First, the ideal flame retardant for fabric treatment should

cause the fabric to have the following characteristics:

1. Will not support combustion, i.e., is self extinguishing.

2. No minimum change in flammability with use, laundering,

or cleaning.

3. Does not differ in appearance or performance properties

of fabrics end use.

4. Be free of toxic, allergenic, or irritating effects.

5. Moderate cost increase when compared to fabrics accepted

for this specific end use.

23

Secondly, the ideal process of applying the flame retardant

should have the following characteristics:

1. Formulated from efficient and economical chemicals,

readily available on the market today.

2. Applied in commercial equipment without unusual requirements

in processing.

3. Be applicable to a broad spectrumi of fiber substrates.

4. No effect on other [rocessing seeps, for example, dyeing

and finishing operations.

5. Durable under all conditions encountered in use.

These are, of course, ideal characteristics and have not been

met by any flame retardant treatment currently practiced in the textile

industry.

Present Status of Flame Retardant Treatments for Cotton and Cotton Blend Fabrics

1. Treatments Based on Simple Phosphorous Compounds

The addition of water soluble inorganic phosphates to the

product is the simplest and least expensive method for improving

the flame retardancy of cotton fabrics. These Inorganic phosphates

differ significantly in their ability to reduce fabric flammability

as can be seen from Table 7 (41). The relatively higher effective

ness of ammonium phosphate has led to the rather wide spread use

of diammonium hydrogen phosphate in treatm.ent of low cost cotton

textile products. This material probably reacts with hydroxyl

groups of the cotton substrate as indicated belov;:

24

Table 7. Amount of Phosphorous Material to Render Cellulose Ncnf lanunable (41).

Parts/100 Parts Substance of cellulose

Ammoniura phosphate 4.5

Sodium phosphate 30.0

Aluminum phosphate 30.0

Calcium phosphate 30.0

Magnesium phosphate 30.0

25

C^l.i--o^ +C^'H4X^P^4 > HO-

<^u_o OM-K/H3

During combustion, the phosphate groups are very effective

in promoting cross-linking of the substrate cotton. The addition

of 5 percent diammonium phosphate will reduce the tarry distillates

from 55 percent to 5 percent of the weight of the original cotton (42)

Thus, a significant increase in the char yield is obtained v/hen

this material is added to cotton. The greater effectiveness of

the ammonia containing phosphates is probably due to the quantities

of gases produced by heating of these materials. The dry gas

produced during pyrolysis of cotton treated with ammonium dihydrogen

phosphate is shown in Table 8. The large quantities of ammonia

undoubtedly serve to dilute the oxygen present and therefore reduce

the amount of energy available from oxidation of the gaseous decom

position products (43).

In some commercial formulations, urea is added with ammonium

phosphate in the flame retardant treatment (44). In these systems

the urea probably acts to increase the quantity of gaseous products

(by giving ammonia and CO^) during combustion.

26

Table 8. The Effect of Aramoniura Dihydrogen Phosphate Retardant System on the Amount of Dry Gas Produced During the Pyrolysis of Cotton Fabrics (43).

Quantity or Gas Loss %

Addition By Weight

0 1.8

0.5 6.0

1.3 6.1

3.1 6.4

6.6 17.6

17.2 14.5

mgs/cm Chemical Addition By Weight Fabric

Ammonium 0 1.8 0.46

dihydrogen 0.5 6.0 1.52

phosphate 1.3 6.1 1.56

1.63

4.45

3.19

2

27

Unfortunately, the inorganic halides all suffer from a common

problem -- they are water soluble and the flame retardancy effects

persist only if the material is not exposed to water. These treat

ments, therefore, show little resistance to normal laundering

conditions and for this reason are not generally acceptable under new

government regulations.

Phosphorous Nitrogen Compounds

Some of the most successful flame retardant treatments aevelopeJ

for cotton are based on use of phosphorous-nitrogen compounds, a

combination showing a large synergistic effect. The compound which

has received the major attention at the present time is tris(l-azi-

ridinyl)phosphine oxide, commonly called APO. The structure of this

compound is shown below:

CHa. O rtai. V J /t

K II /I - P - .

c^.

CW z::::^cH.

APO can react with the hydroxyl groups of cellulose by a ring opening

mechanism as shown below (45).

M O yP "

L ^f^ \ ^ CELL-0-CH,CH2.-Vl-P-H

ct\y^ oM-

oo i^U

Further reaction of the two remaining aziridinyl rings can also

occur producing a tightly cross-linked structure.

A typical formulation based on APO for application to cotton

fabrics is given below:

APO 20.0 7o Thiourea 13.0 % Wetting agent 0.5 % Polyethylene emulsion (307o solid) 3.5 % V/ater 63.0 %

A wet pick-up of approximately 70 percent is typical for treatment

of an 8 oz. per square yard cotton fabric.

The thiourea present in the formulation is also capable of

reacting with the aziridinyl ring. The function of the thiourea

is probably to increase the chain length between cross-]ink points

and thus reduce the brittleness which is imparted to the cotton

fabric. The patent literature contains many references (46) to

formulations based on APO. A number of references suggest use

of ethylenediamine, phosphorous isocyanates, and pentaerythritol

based phosphate esters among other compounds with APO in treatment

of cotton fabrics.

Treatments Rased on Tetrakis (Hydrcxymethyl) Phosphonium Chloride and Its Derivatives

The most widely used treatments for improving flame retardancy

of cotton and cotton blend fabrics is based on tetrakis hydroxymethyl

phosphonium chloride. The chemical structure of this compound is

sho\7n below:

29

HO \

CHa

1 +

H O — CH_ — p CHx-oH

CH iz. I H O

CI

y

Like APO, THPC is capable of reacting with hydroxyl groups on the

cellulose backbone. THPC is always added in the presence of urea,

ammonia, methylol melarnine, or other nitrogen containing compounds

with which it is capable of reacting to form a polymeric structure.

The polyiTierization of the nitrogen and phosphorous compounds is

carried out at elevated temperatures (of the order of 140 C)

usually in the presence of a catalyst. The mechanism of p.ction

of THPC - amine compounds is probably very similar to that

previously discussed for APO-amine type flame retardance.

A typical formulation used in treatment of either cotton

or cotton blend fabrics is given below:

THPC Trimethylolmelamine Urea Triethanolamine Wetting agent Water

15.0% 10.0% 10.0% 2.5% 0.5% 62.0%

(47). After padding on the fabric at the appropriate concentration,

the material is dried for 4-1/2 minutes at 140 C. Some more recent

formulations have suggested use of approximately a 1:1 mixture of

APO and THPC. This formulation is reported to have high efficiency

at a low addition and to provide very good flame resistance.

30

TreaLments Based on Phosphorous-Halogen Compositions

A fev7 workers have suggested flame retardant systems based

on phosphate esters in combination with halogen compounds. One

process which has received considerable attention was developed

by the Southern Regional Research Laboratory of the United States

Department of Agriculture (48). The suggested formulation is

shown below:

(CH2 = CKCH^O)^PO 18.97o

CHBr

(-Cli -CHOH-),

NaHCO„

K^S^Og

13.2%

0.6%

2 .4%

0.6%

64.3%

This formulation is padded on cotton fabrics of 8-9 ounces per

square yard from a water emulsion with a dry addition of approxi

mately 22 percent. Polymerization of the allyl groups is initiated

by the potassium persulphate to give the following structure:

Q-r^Q c«o~-cH

CM. I O 1

C

M

This flame r e t a r d a n t system i s not be l ieved to be r e a c t i v e wi th the

c e l l u l o s e s t r u c t u r e but to simply provide a polymeric s u r f a c e coa t ing (49

31'

A formulation based on tris (2,3-dibromopropyl)phosphate has

been suggested as a flame retardant for military fabrics. This

compound is very insoluble in water and must be added to the fabric

from an organic solvent such as perchloroethylene (50). A dry

solids addition of 25 to 35 percent gave fabrics with fair to good

flame resistance with no after glow.

A number of formulations have been described based on phos

phorous, nitrogen, and halogen compositions of the general form

(PNX^) . These formulations are in a very preliminary stage of

development and have not achieved wide usage on a commercial

scale (51).

Problems V7ith Current Treatments

Ail of the flam.e retardant treatments described above have

deficiencies which prevent their wide spread use on cotcon and

cotton blend fabrics. The halogen compounds tend to give a

yellowing of the fabric which necessitates a further treatment

to produce an acceptably white material. Halogens in combination

with antomony oxide produce excellent flame retardancy with good

durability. Application has been limited to military fabrics

primarily because of the high cost of this system. The fiber

reactive systems based on THPC and APO all have one problem in

common. These treatments can reduce fabric tensile strength by

as much as 20 to 30 percent (52) and produce fabrics with a rough

hand. In addition, APO has undesirable toxicological properties

and catalysts used for some polymer cure steps can give undesirable

fabric color.

Thus, none of the current flame retardant treatments can be

considered ideal for a broad range of textile materials. As a result,

only a few military and institutional applications use fabrics that

are treated with durable flame retardants (53). The present work

was therefore undertaken in an attempt to develop a flame retardant

formulation capable of giving acceptable flame retardancy charac

teristics to cotton and cotton blend fabrics and which would be

reasonably durable under typical laundering conditions. A further

requirement was that this sysceni must be capable of being applied

in commercial fabric treatment machinery from a water based system.

A treatment procedure wa;^ selected which was expected to give

only minimum changes in hand, color, mechanical properties and

aesthetic appearance of treated fabrics. It was also required

that the treatment produce a reasonably priced fabric under

current market conditions. These rather stringent goals for

the flame retardant treatment were established since treatments which

do not meet these criteria are unlikely to gain sufficiently broad

use to contribute to reduction of burn deaths and injuries in the

United States.

The Approach Taken in the Current Work

Many of the undesirable properties of flame retardant treat

ments such as poor hand and loss in tensile strength are undoubtedly

related to the fact that these systems cross-link the cellulose in

the cotton fabric. This work, therefore, attempted to find a flame

retardant treatment which does not depend on reaction with the fiber

to achieve durability. This requirement necessitated the selection

3:

of non water soluble materials for the flame retardancy treatment

since water soluble compounds would be readily removed from the

fabric by V7ashing. Tris (2,3-dibromopropyl)phosphate is a compound

which has these requirements and which in previous work had shown

good flame retardant properties when applied to 100 percent poly

ester fabrics. A major problem with this material was a need for

discovering methods for applying the compound from a water based

system.

The work with tris (2,3-dibromopropyl)phosphate on 100 percent

polyester fabrics suggested that desirable flame retardancy pro

perties could be achieved at 25 percent addition (54). This

required level at the cost-per-pound for tris(2,3-dibromopropyl)

phosphate is consistant v;ith the cost requirements for a comjnercial

process (55).

In an attempt to improve the durability of the flame

retardancy treatment, some formulations west investigated which

included a polymeric binder to entrap the tris(2,3-dibromopropyl)

phosphate on the fiber substrate. A polyacrylic acid-methacrylic

acid emulsion which is in common use in textile processing (56) was

selected for this purpose.

This new, non-reactive flame retardant system both with and

without a polymeric binder was compared with several standard flame

retardant treatments both as to its effectiveness in reducing

flammability and in the relative effects on fabric properties.

34

CHAPTER III

EXPERIMENTAL PROCEDURES

Materials Selected for Study

Both cotton and cotton-polyester blend fabrics were selected

as substrates for testing flame retardant treatments. The cotton

sample was an unfinished twill fabric of 8.5 ounces per square yard,

which is an average weight for general applications. This particular

fabric v/as selected because much of the earler work on flame retar-

dants was done using very similar type samples. The blend sample

was a 65/36 polyester-cctton fabric with an average weight of

three ounces per square yard. Fabric of this construction is

widely used in shirts, blouses, and many other apparel applica

tions. Similar samples have also been used in evaluation of flame

retardant treatments (57).

The basic component of the flame retardant formulation,

tris(2,3-dibromopropyl)phosphate, was obtained from Michigan

Chemical Corporation and was used without further purification.

The chemical and physical properties of this material are shown

in Table 9.

After a number of screening studies, two surface active

agents were selected for the flame retardant formulation. These

surfactants were Triton X-45, which is a nonionic surfactant based

on octylphenoxyethanol, and Triton X-100. Both of these materials

are produced by Rohm and Haas Company and their properties are given

in Table 10.

3:

Table 9. Chemical and Physical Characteristics of the Tris (2,3-Dibromopropyl) Phosphate

Chemical Name

Structure

General Description

Molecular Weight

Density

Viscosity, C3 at 25 C

Color (APIIA)

Solubility

Tris(2,3 Dibromopropyl) Phospha

r H H H H-C - C - t - 0

i t •

Br Br

0

y

Very viscous liquid with light yellow color

697.7

2.2 to 2.3 g/cc or 18.4 to 18.6 5) /gallon

3900 to 4200

25-125

Insoluble in water, miscible with CCl , CHCl^CH^Cl^

J (

Table 10. Properties of Triton X--45 and X-100 Etnulsi: fying Agents with Non-Ionic Character

X-45 X-100

Appearance Clear liquid Clear liqu

Active Ingredient 100% 1007o

Chemical Constitution Alkyl aryl polyethoxy ethanol

Alky aryl polyethoxy ethanol

Specific gravity at 25 /25 C 1.032 to 1.042

Viscosity in Centistokes at 100 F

120.90 Viscosity in Centistokes at 100 F

Solubility Insoluble In Completely water above Soluble in most organic solvents

.2% soluble in' water

Average Chain lengths of the Polyoxyethylene 5 8-10

37

The basic binder material selected for the formulation was

Seycorez C-13, a commercially available emulsion of poly(acrylic

acid) and ester derivatives of poly(acrylic acid) and poly(methacrylic

acid). This emulsion was supplemented by addition of Acryloid B-82

a poly(acrylic acid) produced by Rohm and Haas Company (58). Pro

perties of the binder com.ponent are given in Table 11.

Formulation of the Flame Retardant Emulsion

The principal component of the flame retardant formulation,

tris (2,3-dibromopropyl)phosphate is not soluble in water. Since one

of the objectives of the current work was to prepare a formulation

that could be applied from a v/ater based system, the first major

problem v/as to discover means for dispersing the tris(2,3-dibromo-

propyl)phosphate in a water phase. The tris(2,3-dibronopropyi)

phosphate, being a high molecular weight compound, requires a

surfactant for dispersion similar to those used in solubilizing

high molecular V7eight oils. After screening a large number of

surfactants, it was found that two per cent of Triton X-45 based

on final formulation gave a good dispersion of the flame retardant

in v/ater. However, this emulsion was not stable when other compo

nents of the flame retardant formulation were added. Further

experimentation revealed that a second surfactant, Triton X-100,

was necessary to give a stable emulsion. The final form.ulation

used in flaue retardancy testing was compounded as follows:

1. The flame retardant tris(2,3-dibromopropyl)phosphate

was thoroughly mixed with two per cent Triton X-45 and added to

water with vigorous agitation.

38

Table 11. Chemical and and Acryloid

Physical Characteristics of B-82

Seycorez C-13

C-13 B-82

Appearance Milky emulsion Solids

Solids 46% 1007o

Specific Gravity 1.06 1.16

Viscosity 1.000 cps at room temperature

300-600 cps at 25°C

Chemical Constitution Acrylic polymer emulsion with non-ionic characteristics

ester derivatives of acrylic and methacrylic acids

Solubility Dispersed in water Toluene

39 \

2. IVo per cent Triton X-100 was dissolved in water with

continuous agitation.

3. The retardant solution was mixed slowly with the X-100

water soli'tion with vigorous agitation.

4. The poly (acrylic acid) solution, Seycorez C-13, is added

to the above solution.

5. P'inally the Acryioid B-82 which had been previously

dissolved in toluene was added LO the e/.iulsion system.

Hie composition of the final Lornulation is given below:

Tris (2, 3-dibroiriopropyl) phosphate 32.5%

Triton X-45 2.0%

Triton X-100 2.0%

Seycorez C-13 30.0% -

Acryioid B-82 2.0%

Toluene 19.0%

Water 12.5%

100%

The procedure described above gave an excellent emulsion with

no settling or break-up on standing for periods of several v/eeks.

As much as 65 per cent of the flame retardant compound could be

included in the formulation without reduction in stability of the

emulsion. However, in the present work only 32.5 per cent of the

tris(2,3-dibromopropyl)phGsphate v/as used in order to keep the price

of the formulation in a reasonable, comr.iercially acceptable range.

Application of the Flame Retardant System

The flame retardant system described in this work, %as well

40

as the control systems described below, were applied to 8" x 15"

rectangles of the 100 per cent cotton twill and 65/35 polyester-

cotton blend fabrics . Retardants were added to the fabric by a

padding operation on a H. W. Butterworth & Sons Co. machine with

three rubber pressure cylinders adjusted for 20 pounds pressure.

Each sample was padded twice. After padding, the samples were

placed on aluminum frames and placed in a Part low oven for drying

at 250 F for seven minutes. Samples that required curing were

placed in an oven at 325 F for tv/o minutes.

Reference Samples

In addition to the samples treated with tris(2,3-dibromopropyl)

phosphate both with and without a poly (acrylic acid) binder, several

control samples were prepared using standard flame retardanL treat

ments for comparison with the formulation under investigation in

this work. Details of the treatments of these control samples are

given in Appendix A. Samples 1 and 2 are cotton and polyester-cotton

fabrics, respectively, used as controls to evaluate changes in the

fabrics resulting from various flame retardant treatments. Samples 3

and 4 are cotton fabrics treated with phosphoric acid or inorganic

phosphate salts. These samples are representative of low-cost flame

retardant treatm.ents currently used in the textile industry. Samples

5 and 6 are cotton and cotton-polyester blend fabrics treated with a

flame retardant formulation based on TKPC. These samples are repre

sentative of the better flame retardant treatments in use at the

present time. Samples 7 and 8 are cotton and cotton-polyester

blend fabrics treated with a formulation containing

41

tris (2 ,3-dibromopropyl)phosphat;e without an acrylic binder. Samples

9 and 10 are cotton and polyester-cotton blend fabrics treated with

tris(2,3-dibromopropyl)phosphate and a poly(acrylic acid) binder to

improve the durability of the flame retardant treatment.

Testing

Flammability Tester

The flammability of all fabrics V7as determined by a procedure

essentially identical to the American Association of Textile Chemists

and Colorists Test Method 33-1962. Samples 2" x 6" were tested

after laundering for one, five, and ten times in order to determine

the durability of the flam.e retardant treatment (59). In the AATCC

test method, samples are inclined at an angle of 45 degrees and a

flame is applied to the surface near the bottom edge. The time

required for the flame to burn upward along the sample a distance

of five inches is recorded. This test was designed to identify

fabrics which ignite easily or which burn with sufficient intensity

to be hazardous when used in apparel. The length of char, the

burning time, and the existence of after glow are all important

aspects which can be determined from this test. Apparel fabrics

are usually dividedwith regard to flammability into the following

classifications:

Class 1: Normal flammability with no unusual burning

characteristics.

Class 2: Intermediate flammability.

Class 3; Rapid and intense burning. Fabrics in this classifi

cation are considered dangerous for v/earing apparel.

42

Durability

Because of the chemical action of calcium in water and the

solubility of some components of flame retardant finishes, the

durability of a flame retardant treatment is an important charac

teristic. The most common test of durability is a measurement of the

change in flammability characteristics after laundering. All samples

in the current work were submitted to the following laundering process.

Samples were placed in a Kenmore automatic washer set on the normal

cylce. Agitator speed was 70 cycles per minute, washing time was

12 minutes, with a rinse temperature of 40 C. Regular Tide deter

gent (200 grams per batch) was used. After the washing the samples

were dried in a Kenmore Model 600 automatic dryer with exhaust

temperature ret at 60-70 C and a drying time of 40-45 minutes.

Flammability of the samples was determined after one, five and

ten washes (60).

Color

Change in color of textile fabrics as a result of flame

retardancy treatments is an important characteristic. Yellov/ing

often occurs and is very undesirable. A yellowness index of all

samples was therefore determined before and after treatment.

These measurements were made on a Photovolt Reflectometer Type 670.

The yellowness of a fabric can be determined using this

instrument by measuring the reflectance of light from the sample

in the Red (amber), Blue, and Green regions of the visible spectrum.

The yellov;ness index is defined by the following expression:

43

Yelio Tness Index = R(ambcr reading) >^ R(blue readin,g)_ R(green reading)

On the yellowness index scale a value of 0 is associated with a perfect,

white sample. High values represent increasing degrees of yellowness.

Hand

Hand is a characteristic of textile fabrics which describes the

"feel" of the fabric \-7hen touched by the fingers. There is no quanta-

tivc measurement of hand but terms such as soft, rough, stiff, smooth,

etc. are generally used to describe the hand of a fabric. The hand of

the fabrics before and after treatments to improve flame retardancy

were evaluated (61).

Tensile Strength

An extremely important property of any fabric treatment is its

effect on the fabric tear strength. Tear strength of the cotton and

polyester/cotton fabrics used in this work were tested untreated and

treated by the Elmendorf method. Because it depends on gravity for

its operation, this technique gives consistant tearing strength

results (62). The instrument used in this work V7as a Model NBS of

3200 grams capacity. Tearing strength measurements were made along

the warp and along the filling directions on 2-1/2" x 4" samples.

VJrinkle Recovery Test

Crease recovery is also a very important characteristic of

textile fabrics. Crease recovery is defined as the speed with which

a fabric recovers from creases. The effect of flame retardant treat

ments on the crease recovery of the cotton and cotton/polyester blend

fabrics was determined with the Monsanto wrinkle recovery method (63).

The figures reported in this work are the averages of the crease recovery

in the warp and filling directions.

A4

CHAPTER IV

RESULTS AND DISCUSSION

A suiTimary of the results of tests on the original reference

sample and sair.ples given the five flame retardancy treatments are

shown in Tables 12-16. A more complete description of results and

pictures of samples following the flammability test are given in

Appendix A.

Results of Flammability Tests

As indicated in Table 12 fabric samples of both cot.ton and

55/35 polyeste-r-cotton blends burn completely in a few seconds in

Lhe flammability test. Considerable improvement can be made using

simple flame rctardant treatments based on phosphoric acid and

diainmoniura phosphate. However, the improvement in flammability

is not durable. Samples after five Tvashes burn completely as

quickly as for untreated samples. The samples treated with tris(2,3-

dibromopropyl)phosphate without an acrylic binder show little

durability of the flame retardancy treatment on the cotton sample.

The tris(2,3-dibromopropyl)phosphate is apparently much more sub

stantive to the hydrophobic polyester fiber even withoiit a binder.

However, this treatment would not be acceptable on 100 per cent

cotton samples. The tris (2,3-dibromopropyl)phosphates with an

acrylic binder gave results very comparable to the treatment based

on THPC. More extensive durability testing would be necessary to

distinguish betweeen these two treatments. The tris(2,3-dibromopropyl)

'4^

phosphate treatment with the acrylic binder shows remarkable durability

in view of the fact that this is a non-reactive treatment.

Results of Color Measurements

The flame retardancy treatments investigated in this study had

very little effect on color of the fabrics with the exception of the

treatment based on tris (2,3-dibrcmopropyl)phosphate with ths acrylic

emulsion. The reason for the increase in yellowness due to this

treatment is not clear. The tris (2 ,3-dibromopropyl)phospiia te is

a light straw yellow compound but this apparently is not the reason

for the color change since the sample without the acrylic emulsion

shovzs little change from the original reference sample. Apparently

the acrylic emulsion is responsible for the color change. This

aspect of the treatment suggested in this work will require further

investigation if the treatment is to become comruercialiy acceptable.

The yellov/ness index measurements on all the polyester/cotton blend

samples are considerably higher than expected based on visual

observation of the samples. This discrepancy is undoubtedly due

to the fact that polyester is optically brightened by the manufacturer

and this characteristic is not adequately accounted for in the Photo-

volt Refleetometer.

Evaluation of Fabric Hand

Only the treatment based on THPC and on tris(2,3-dibromopro-

pyl)phosphate with an acrylic emulsion significantly influence fabric

hand. Both of these treatments caused an increase in the stiffness

of the fabric. The tris (2,3-dibromopropyl)phosphate formulation

might be improved by the addition of a suitable softener in the

46

formulation. Such a softener is a part of the formulation based on

THPC. It would be expected that less change in hand should result

from the tris(2,3-dibromopropyl)phosphate treatment since this

material is not expected to cross-link the cellulose structure.

Some improvements in hand might therefore be achieved with slight

change in the formulation.

Fabric Tensile Strength

As can be seen in Table 15, treatments based on THPC,

diammonium phosphate, and phosphoric acid all significantly reduce

fabric tensile strength. The formulations suggested in this study,

however, show little reduction in fabric strength. Thus, the non-

reactive flaiao. retardant treatments have a significant advantage

in this important fabric property.

Wrinkle Rocovery Results

The flame retardancy treatment based on tris(2,3-dibromopro-

pyl)phosphate v/ith the acrylic emulsion gave the best wrinkle recovery

results of any of the samples tested. The treatment based on TKPC

also gives very good results in the wrinkle recovery test.

Conclusion and Recommendation

This work has demonstrated that semi-durable flame retardancy

can be imparted to cotton and cotton/polyester blend fabrics by use

of a non-reactive treatment system. Cotton fabrics do require

inclusion of a polyacrylic acid binder in order to achieve this

durability. Such non-reactive systems have advantages both in

sim.plicity of application and in retention of physical properties

of treated fabrics. The flame retardancy formulcition can be applied

4 7

from a water base system on equipment that is standard for treatment

of textile fabrics.

There are certain deficiencies in this flame retardant treatment.

First, the increase in yellovmiiss of treated fabrics should be inves

tigated. This phenomenon cou]d have been a resu]t of the particular

polyacrylic acid emulsion batch used in this study or it could be a

fundamental problem with this particular system. The increased

stiffness of the fabric after treatment with this formulation is

also problematical. This aspect of the flame retardancy treatment

might be improved by inclusion in the formulation of a suitable

fabric softener.

Attempts were made during the course of this work to obtain

differential thermal analyses curves for samples given the various

flame retardancy treatments. However, the instrument available at

the A. French Textile School was not sufficiently sensitive to

permit recording of acceptable DTA curves for these samples. An

investigation of differential thermal analysis and thermogravimetric

analysis should reveal information about the mechanisms of flame

retardancy of these formulations.

A3

4J

c u 0)

M-l M-l

1)

IS

OT

3 OT ( U

pc:

Xi CO

i—l Pt4

0} 0) C

> o •r^ ^ 4-1 - p to ca >-l r - l CO 3

B tl o o

CN4

rO CO

H

m M u u CO CO

J:: CO

x : CO

x : m cj s: o x : o x : v>0 4J

= W)

4_)

= W) 4-1

= 6 0 CO cvj d CN d 0 0 C (U •~-- 0) • ^ oj •~-- 0)

C/5 r-( r - l r - l , -^ m r - l

CO : 2 c i n

• CO CO O C 3 cu 'O a , 13 r-* o X> • S d E d

4-1 »» CX, CO o o o o 4-1 a, E -3 G <J o o O 4 j O C 0) -i

3 o M 3 CO u:^ <+ PQ i n

m CO

4J

>-i

CO

J : :

M CO

x ; m o •r-l t o •^-- 0) •~-- oi

X : , P -r-l r n i-H en ' - I CO

ca S

• W • CO • CO i n c D, 13 a , ^3 CL, ^ 3 u

o E d e c c d CO 4-» o o o o 4-1 o o x : 4-> o o CJ O O (U U CJ U -C o 0) a; d 4J OJ ->-i

o d CO d CO TW d v) = 6 0 v-i ^1 -^ d • < CM d 3 en 3 i n • H (JO J ^n •~-- <L»

M en « <n .Cl -r^ rt v + r-; r - l

m

• CO

a, 'O e d CO o o 4-1 + j 4J

•~~ o o O O 0) m 0) d -M d -u d 4-1 v>0 d CO •.-I •r - l •H

>- 'O d • J d •x> d 3 m •r-l bO •H t o •H t o

x : PQ r - l Q -H a •r^ P 'r-i

CO CO

^ r - l • CO 73 CO

c O, 13 v-i >-i OJ 13 o E d CO CO F g 4J O O s: x i 4J >-i O • u 4-> o u u j : : o x i o <u 3 O O QJ O 0) 4-1 + j d 4J PQ (U d -u O d CO : 60 = CO •r-l CO •r^

u CM d <}• d 13 d 5 ^ - 3 C 3 CO •~-- 0) ---~ 0) T-l W) O CO •r^ t o

CO i n .—1 r^ m r - ( Q -r^ r-- i n Q -r^

X ) d d -r^ d -< d - d d - d B d E

o <c T4 W

O " O ffi o o 0 0 "TD

o <c T4 W • H CO •r^ O •r^ O •r^ 0

1) ^ « 4_l 0) 4-1 CO 4-1 4-1 4-) CO CO U CD S CO 0) "^ ^ u CO i-H " ,-H J3 r-H •-H d "^ ^ u - o

3 -r^ ^

fi 0 2 d o m O < cv; o o i

P4 H O ^4 0 V4 ^

fo X> - ^ ^ 1 fo ffi p4 « : s o o i P4 H PM ^

0 V4 ^ fo X> - ^

49

OJ

• H

> f^^ X OJ

X ! C

M

w CO

 M CO O r H

i H r> O R

O M o (U 1^

> •H 4J 4-» c c« (1)

M M CO a; C X i W y <4H

o • H

o Q

00

rQ CO H

to 0)

^rj CD cd :s o i-H

m en

LA v D

CO

CN

1 1 1

1 1 f

CSJ

-cf

0 0

CM

-cf

rs . to 0)

^rj CD cd :s o i-H

C!

o 4J 4J O

u

CO

1—(

OS

»—( CJN

»—1

CO

T-i

CO

r—1

O

0 0

c« (1)

m o-i

LA v D

CO

fNj

1 1 1

1 1 1

O

i n

CO

CM

-cf

Ul

: 3

m r:;

O 4J 4J o o

CO

r—1

CO

r—1

<~o CO

r - l

CO

t—t

O

w cd

uo f O

-. i n >x>

\ 0

1 i 1

1 1 1

i n

CT\

0 0

vO

oc

C7\

r—1 o 4-» XJ O

o C>J

c><

CO

m

CM

«n

<r>4

»n

CM

X I -i S QJ U -U O CO Pk IS 1

CO a; u

Cl

C )-( O V

u X > CO 0) :s U) CO X >

r Q C CO

O X> • H - H •U O CO <

i-H D O S - H G ^1

o o

o CO

O P M

:ii H d o

X ) -i (y O M

P4 ; :3

d)

•H 6 o M

ri3

<i) r C XJ

r d XJ • H :5

c o

• H 4J X > CO C

r-i r) D O g B-»-< e o o

PM O

(U

• H

e o u

rQ

'^rS XJ

•t!^ ^ - d a ^ o «

• H 4J t S CO d

^^ 0 0 O

E §• o o

PM U

50

Table 14. Comparative Hand Results v/ith Different

Formulations

Formulation Applied

1 Wash 5 Wa shes

Formulation Applied

1 Cotton 65/35 Cotton 1 65/35

itreated reference Soft Soft Soft 1 Soft

• rmulation based on H^PO, , ;A, Water Soft Soft

trrriulation based on Di\P, Urea, •ric Acid and Water Soft Soft

•rraulation based on THPC, NaOH, ea Stiff Stiff Soft Stiff

irnulation with the bromine impound

Soft Soft Soft i Soft

irniulation with the bromine •mpound and binder Stiff

. j

Stiff Stiff Stiff

Table 15. Comparative Strength of Treated and Control San^ples: Results in Per Cent Strength Retention

51

1 Wash

Formulation Applied Cot :on 65 /35

•

F \v F W

Untreated reference 100 100 100 100

Formulation based on b'-iPO , DEA, Water •J i^

72 73 _.. —

Forinulaticn based on DAP, Urea, Boric Acid and Water

76 94 __

Formulation based on THPC, NaOH, Urea 64 96 97 76

Formulation with the bromine compound 88 93 100 88

Formulation with the bromine compound and binder

81 100 55 45

rC i J • H

• >

»-• W o o >-l W) >-. 0)

> o o a c^ .

w H > • K 4J 4J c td <u »-i u cJ CJ Cu u^ 6 ^4-1

o •r-J

u Q

rC)

H

to OJ

[2

OT td

LO

LO

o 4-1

o CJ

in ro

LT) vO

o • M

o u

P4

P4

in 1 I ^-t- f 1 ^•J I 1

—1 1 1

rsl ON

O CO

rsl

CO

ON

o

m ON

m r

r

in en

oi

00 CJs

o Ol

o • v j -

o

o oo

o o

<3-

o

i n

o in

o en

o •n

in in

i n

< w 03 o X ) Q 0) cd o; u z 0) (U

• H #v 1 3 d c t H •<r M ' H • H Ci. O #k u e g P.

< Pu m S P-J o G

M w W Q H ^ r Q

o d) C a ;-i C (1)

•5 i • H o o o a; o X •5 i 4-t c U + j •5 i c« -i <u <u IS d) , a ^.5 3 a; w w CO +-I

^.5 s ^4-1 cd CO X ) cd • H

^.5 u o .o

d

r Q cd

r-l

^ - o

•X} o o X ) O o

^ - o

0) • H • H • H • H • H • H 4-t U •M O 4-t U T J 4-J X )

« cd CO < CO Cd C Cd rt d) r - l t - l .- r H :3 r-i d >-l a V4 ri o g a o rJ o u 0) e • H s cd E ex 6 cu c >-l 4-t M >-i > - l -i O o o o

PM IS p cq i^ ;=) PM a ^ o

53

APPENDIX

54

Sample 1

A. Flame retardant formulation None

B. Material used Cotton twill

C.

D.

E. Drying at 250 F 7 minutes

F. Flammability test after: 1 wash Burns completely

in 33 seconds.

G. Color after: 1 wash 2 .5 5 washes 1.3 6 hours at IOO°C 1.3

H. Hand after: 1 wash Fine, soft 5 washes Fine, sof<:

I. Tear strength, in the filling direction 2650 g in the warp direction 3094 g

J. Wrinkle recovery, in the filling direction 81 in the warp direction 97

After 10 washes, in the filling direction 80 in the warp direction 92

Sample 2

55

A. Flame Retardant Formulation

B. Material used

C.

D.

E. Drying a t 250°F

F. Flamraability t e s t a f t e r : 1 wash

5 washes

None

65/35, polyester/cotton

7 minutes

Burns quickly in 15 seconds. Substrate completely charred and volatilized. Burns completely In 15 seconds. Black smoking.

G. Color after:

H. Hand after

1 wash 5 washes 6 hours at 100°C

1 wash 5 washes

I. Tear strength, in the filling direction in the warp direction

J. Wrinkle recovery, in the filling direction in the warp direction

After 10 washes, in the filling direction in the warp direction

6.7 2.8 2.8

Fine, , soft Fine, , soft

992 g 1376 8

141' 142'

145' 144'

56

Sample 3

A. Flame Retardant Formulation 75% HoPO, 58% Di-EtiHanol- .

amine 39 Water 3

B. Material used Cotton twill

C. Wet pick up 81%

D. Weight i n c r e a s e 20%

E. Drying at 250 F 7 minutes

F. Flammabili ty t e s t a f t e r : 1 wash 1/2" char length.

No after glow. No smoking.

5 washes Burns completely in 33 seconds. No aft'ir glow.

G. Color after: 1 wash 3.2 5 washes 1.3 6 hours at 10C°C 1.9

H. Hand after: 1 wash Fine, soft 5 washes Fine, soft

I. Tearing strength, in the filling direction 1920 g in the warp direction 2272 g

J. Wrinkle recovery, in the filling direction 95^ in the warp direction 69

Sample 4

57

Flame Retardant Formulation

B. Material used

C. Wet pick up

D. Weight increase

E. Drying at 250°F

F. Flaminability test after: 1 wash

5 washes

G. Color after 1 wash 5 washes 6 hours at 100°C

Water 67% Diammonium phosphate 20%

Urea 6.5 Boric Acid 6.5

Cotton twill

100%

20%

7 minutes

3/4'' char length No after glow Burns complC'iGly in 35 seconds. N'o after glow.

2.5 1.3 1.9

H. Hand after: 1 wash 5 washes



Fine, soft Fine, soft

2016 g 2496 g

74° 75°

Sample 5

53


B. Material used

C. Wet pick up

D. Weight i n c r e a s e

E. Drying a t 250°F and cured at 325 F

THPC 72.37o NaOH 7.2% P.E. emulsion 5.8% Non-ionic surfactant 0.3%

Urea 14.4%

Cotton tvrill

80%

65%

7 minutes 2 minutes

F. Flammability test after: 1 wash 5 washes 10 washes

Did not ignite Did not ignite Ignited in 45 seconds

G. Color afrer: 1 wash 5 washes 6 hours at 100°C

2.5 1.3 1.3



J. Wrinkle recovery, in the filling direction in the v/arp direction

Stiff Soft

1696 g 2560 g

120° 98°

Sample 6

59


B. Material used

C. Wet pick up

D. Weight increase

E. Drying at P.SO' F and cured at 325'^F

F. FlanuT.ability test after: 1 wash 5 washes 10 washes

cO,

TIIPC NaOH PE. emulsion Non-ionic

surfactant Urea

72, 7. 5.

0, 14,

.3%

.2% ,8%

,3% ,4%

65/35, polyeG ;ter/cotton

80%

65%

7 minutes 2 minutes

Did not ignite Did not ignite Only '>y i.ich of char length.

G. Color after: 1 wash 5 washes 6 hours at 100 C

9.5 5.0 4.2




Stiff Stiff

960 g 1056 g

124° 135 ^

Sample 7

60


B. Material used

C. Wet pick up

D. VJeight i n c r e a s e

E. Drying a t 250°F

F. Flammabil i ty t e s t a f t e r : 1 wash

5 washes

10 washes

T-2,3-DBP 45.0% Triton X-45 5.0% Triton X-100 6.0% Water 44.0%

Cotton twill

100%

47%

7 minutes

Ignited in 58 seconds. No intense burning. No after glow. Burns completely in 46 seconds. Burns completely in 40 seconds.

G. Color after: 1 wash 5 washes 6 hours at 100°C

2.5 1.3 1.3

H. Hand after: 1 vzash 5 washes





2336 g 2880 g

104° 79°

100° 80°

Sample 8

61

A. Flame Retardant Formulat ion

B. Material used

C. Wet pick up

D. Weight increase

E. Drying at 250°F

F. Flan TnabiJity tost after: 1 wash 5 v/ashes

10 washes

G. Color after: 1 wash 5 washes 6 hours at lOO C

T-2,3-DBP 45.0% Triton X-45 5.0% Triton X-100 6.0% Water 44.0%

65/35, polyester/cotton

100%

47%

7 minutes

Did not iguite 3/4 inch char length Flame self exting. 1/2 inch char length. Flame self exting.

6.8 2.8 2.8



J. Wrinkle recovery,' in the filling direction in the warp direction



1056 g 1216 g

145° 141°

140° 140°

Sample 9

62

k. Flame Retardant Formulation

Material used

Wet pick up

Weight increase

Drying at 250°F

Flaminability test after: 1 wash 5 washes 10 washes

Acrylic B~82 2.0% Toluene 19.0% Triton X-45 2.0% T-2,3-DBP 32.5% Triton X-100 2.0% Water 12.5% Acrylic emulsion C-13 30.0%

Cotton twill

90%

47%

7 minutes

Did not ignite 1/2 inch length char Burns completely in 50 seconds.

Color after: 1 wash 5 washes 6 hours at 100°C

6,7 4.0 8.0

1. Hand after: 1 wash 5 washes

Tear strength, in the filling direction in the warp direction

f. Wrinkle recovery, in the filling direction in the warp direction


Stiff Stiff

2144 g 3104 g

134° 115°

130° 111°

Sample 10

63


B. Ma te r i a l used

C. V/et p i c k up

D. Weight increase

E. Drying at 250°F

F. Flammability test after: 1 wash 5 washes 10 washes

G. Color after: 1 wash 5 washes 6 hours at 100°C

Acrylic B-82 2.0% Toluene 19.0% Triton X-45 2.0% T-2,3-D3P 32.5% Triton X~100 2.0% Water 12.5% Acrylic

emulsion C-13 30.0%

65/35 polyester/cotLon

100%

53%

7 minutes

Did not ignite 3/8" length char 3/8" length char Flame self-exting.

9.8 7.4 7.4




After 10 V7ashes, in the filling direction in the warp direction

Stiff Stiff

544 g 576 g

155° 150°

150° 14 5°

64

r^- :. -t V -v* ,p^f:^^-'jf^^

After 1 Wash After 5 Washes sample completely burned

Figure 1. Flammability Test on Cotton Samples Treated with Formulation Based on Phosphoric Acid.

65

After 1 Wash After 5 Washes sample completely burned

Figure 2. Flammability Test on Cotton Twill Samples Treated with Formulation Based on Di-Ammonium Phosphate, Urea and Boric Acid.

66

I r

%

* 5

fr

After 1 Wash After 5 Washes After 10 Washes sample completely burned

Figure 3. Flammability Test on Cotton Twill Samples Treated with Formulation Based on TMPC.

67

.T{

1

>

k

After 1 Wash After 5 Washes After 10 Washes

Figure 4. Flammability Test on 65/35 Polyester/Cotton Blend Treated with Formulation Based on TMPC.

68

k -*<•»

^

After 1 Wash After 5 Washes After 10 Washes

Figure 5. Flaramability Test on Polyester/Cotton Blend Samples Treated with Formulation Based on Tris-2,3 DBP.

69

«L •'• \ ^

xl . -"^'^ :/-

\

After 1 Wash After 5 Washes After 10 Washes sample completely burned

Figure 6. Flammability Test on Cotton Twill Samples Treated with Formulation Based on Tris-2,3 DBF with Acrylics.

70

y*

A * . >A. After 1 Wash After 5 Washes After 10 Washes

Figure 7. Flainmability Test on 65/35 Polyester/Cotton Blend Samples Treated with Formulation Based on Tris-2,3 DBP with Acrylics

71

• i ^ - Glossary of Terms and Definitions Used in Relation to Flame Retardants

Add-on Weight increase of fabric due to absorbed chemical agents in solution. Finished agent might contain the flame-retardant chemical.

After-flarae T- time in seconds which the fabric flames after the source of flame has been extinguished.

After-glow T- in seconds which the fabric glows after all flaming has ceased.

Char area The blackened area resulting after all flaming and glowing have ceased.

Char length This is the furthest distance of the burned damage as measured from the originating poinc of Lhe flame. This may be the lower e.ige of the fabric strip, in the vertical flame test.

Combustion Chemical decomposition caused by a combinacion ol the substances with 0«, given evolution of light and heat in a burning reaction.

Fabric weight May be expressed in onzes/s.y.

Flame retardant, Flame proofing Degree of resistance to ignition and burning;

any chemical substance which gives resistance to flame to a textile material.

Flame test Standard procedures. Flammability test methods in accord with Federal I,aw for Clothing Textiles.

Oxygen index test 0. I. test based on the m.ole fraction of oxygen

just needed to maintain the combustion, or the mole fraction of oxygen in a oxygen/nitrogen atmosphere

0^

(O2 + N2)

72

Pyrolysis Chemical degradation caused by heat; may be accompanied by combustion if carried out in presence of air.

Self-extinguishing is one which ignites and burns when exposed to. a

flame source but goes out immediately or in a short time after the flame is removed; self-extinguishing materials are thus flame-retardant but not all flame-retardant materials are self-extinguishing.

Tenderin action post action of any chemical agent used in the treatment of textile, material which will result In loss of fabric strength.

73

BIBLIOGRAPHY

/4

LITERATURE CITED

1. Information Council on Fabric Flammability, Proceedings of Third Annual Meeting, New York City, 1969, 56-59.

2. Drake, G. L.,"Fire Retardancy: Its Status Today," American Dyestuff Reporter, 60 , 43-47, (1971).

3. McDonald, K. , R. Dardis, F. B. Smith, "Accidental Burn Injuries: A Review," Journal of the American Association of Textile Chemists and Colorists, 3_> 33-37, (1971).

4. Howry, A. K. , "We Don't Know Much About Fabric Flammability," Modern Textiles,50, 56-60, (1969).

5. Weinstein, R., "Current Legislation Requirc-.ments and Test Methods for Flame Retardancy," J. of Atner . Assoc, of Textile Chem. and Col., 3, 55-57, (1971).

6. Dipietro, J., H. Barda, H. Stepniczka, "Burning Characteristics of Cotton, Polyester and Nylon Fabrics," J. of AATCC, 3_> 45-53, (1971).

7. Lyons, W. J., The Chemistry and Uses of Fire Retardants, 24-26, First Edition, Wiley-Interscience, John Wiley and Sons, Inc., New York, (1970).

8. Miles, D. T., and C. A. Delasanta, "Durable Non-Reactive Flame Retardant Finished for Cotton," Textile Research Journal, 38 , 273, (1968).

9. Siu, R. G. H., Microbial Decomposition of Cellulose, 3-13, Reinhold Publishing Corporation, New York, (1951).

10. Conant, B. J.j and H, A. Blatt, The Chemistry of Organic Compounds, 289-293, Fourth Edition, The MacMillan Company, (1957).

11. Morrison, T. R. and N. R. Boyd, Organic Chemistry, 1022-1023, Allyn and Bacon, Boston, Second Edition, (1966).

12. Trotman, E. R., Dyeing and Chemist Technology of Textile Fibers, 44-48, Fourth Edition, Charles Griffin Company Limited, London, (1970).

13. Little, W. R., Flame Proofing Textile Fabric, 46-47, Reinhold Publishing Corp., New York (1947).

75

14. Article on "Fire Retardancy," Encyclopedia of Polymer Science and Technology, Vol. 7, 9-11 and 39-43, Interscience Publishers, a division of John Wiley and Sons, New York, (1967).

#^ 15. ChaCterjee, K. P., "Chain Reaction Mechanism of Cellulose,"

J. of Applied Polymer Science, 12^, 1859, (1968).

16. Madorsky, L. S., "Chapter XII," Therm.al Degradation of Organic Polymer, Interscience Publishers, John Wiley and Sons, New York, (1964).

17. Goodings, E. D., "Thermal Degradation of Polymers," Soc. Chem. Ind., Monograph No. 13, pp. 106, 211, (1961).

18. Goodings, E. D., pp. 106, 211.

19. Goodings, E. D., pp. 214.

20. Marchall, I. and A. Todd, Trans. Faraday Soc. , ^9, 67, (1953).

21. "Fire Retardancy," Enc. of Polyin. Sci . and Tech., 7. 9-11

and 39-43 (1967).

22. Little, W. R., "Flame Proofing Textile Fabric," 7S-S9.

23. Little, W. R., 82-84.

24. Little, W. R., 88.

25. Little, W. R., 80-81.

26. "Fire Retardancy," 16-17.

27. Lyons, W. J., The Chemistry and Uses of Fire Retardants , 24-26.

28. Kirk-Othmer, "Chlorine", Enc. of Chemical Technology, 5_, 1-6, Interscience Publishers, (1954).

29. Lyons, W. J.," 98-101.

30. "Fire Retardancy," 17-18.

31. Lyons, W. J., 210-213.

32. Lyons, W. J., 216-217.

33. Read, J. N., and G. E. Heighway Bury, Flame Proofing of Textile Fabrics, 74, 823-828 (1958).

34. Lyons, W. J., 84-88.

7C

35. Kirk-Othmer, "Boron Compounds," Enc. of Chem. Techn, 3, 609-623, Intsrscience Publishers, (1964).

36. Trotman, R. E. 294-298.

37. Little, W. R., 179-184.

38. Ward, J. K. , Chemistry and Chemical Technology of. Cotton, 443-461, Interscience Publishers, (1955).

39. Drake, L. G., 43-47.

40. Drake, L. G., 43-47.

41. Lyons, W. J., 165-167.

42. Little, W. R., 43-57.

43. Little, W. R., 73-75.

44. Davis, V. F., J. Findlay and E. Rogers, "The Urea-Phosphoric Acid Method of Flameproofing Textiles," J. of TextiJa Institute, 40 , T839 (1949).

45. Leblanc, B. R., "A Durable flame Retardant Finish with APO," Textile Research J. , 35 , 341-346 (1965).

46. Lyons, W. J., 175.

47. Lyons, W. J., 196-203.

48. Prick, G. J, W. J. Weaver, and D. J. Reid, "Flame Resistant Cotton Fabrics: An Emulsion Treatment Using an Organic Phosphorous Bromine Polymer," Tex. Res. J., 25, 100-105 (1955).

49. McQuade, A. J., "Flam.e Resistant of Military Textiles," Amer. Dyestuff Reporter, 44 , 749, (1955).

50. Miles, T. D., A. C. Delasanta, "Durable Non-Reactive Flame Retardant Finishes for Cotton," Tex. Res. J., 38, 273-278, (1968).

51. Lyons, W. J., 184.

52. Drake, G. L., 43-47.

53. Sanderson, W. A., W. A. Mueller, and R. Swidler, "Phos-phonate Finishes for Fire-Retardant, Durable-Press Cotton," Tex. Res. J., 217-222, (1970).

77

f

54. Dipietro, et. al, 45-53.

55. "A Study of Fire Retardancy of Polyester/Cotton Sheeting," Pj-edmont Section, Southern Regional Research Laboratory, Proceedings of the AATCC, 57_, 40-44, (1968).

56. mies, T. D. and A. C. Delasanta, 273-278.

57. Proceedings of AATCC, 57., 40-44, (1968).

58. Rohm and Haas, "Resin Review," XV, Mo. 1, 26-31, (1965) and "Resin Review, XIX, No. 1, 14-15 (1969).

59. Technical Manual of the AATCC, Method 33-1962 (1969).

60. Technical Manual of the AATCC, Method 124-1967.

61. Lundgren, H. P., "New Concepts in Evaluating Fabric Hand," J. of Tex. Chem. and Colorists, 1_, 35-45 (1969).

62. American Association Testing Materials, ASTK, D-1424-63.

63. Technical Manual of the AATCC, Test Method 66-1968.

A NEI'J FLAME I

Documents

Transcript of A NEI'J FLAME I