NBSIR 85-3226

Fire Characteristics of Composite

Materials - A Review of the

Literature

James E. Brown

Joseph J. Loftus

Richard A. Dipert

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Gaithersburg, MD 20899

Issued August 1986

Supported in part by:

U.S. Department of the Navy

aval Sea Systems Command (NAVSEA 05R25)

ashington, DC

GC

100

.1156

NO. 85-3226

1086

NBSIR 85-3226

FIRE CHARACTERISTICS OF COMPOSITE

MATERIALS - A REVIEW OF THE

LITERATURE

James E. Brown

Joseph J. Loftus

Richard A. Dipert

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Gaithersburg, MD 20899

Issued August 1986

Supported in part by:

U.S. Department of the Navy

Naval Sea Systems Command (NAVSEA 05R25)

Washington, DC

U.S. DEPARTMENT OF COMMERCE. Malcolm Baldrige. Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler. Director

Table of Contents

?.§ge

Abstract 1

1. Introduction 1

2. Technical Sources of Information 2

2.1 Evaluation of Referenced Materials 3

3. Criteria for Evaluation of Composite Materials 6

3.1 General Criteria for Choice of Resins 6 3.2 Criteria for Ranking Composites for Fire Resistance 7 3.3 Findings from the Literature 8

4. Summary 16

5. Conclusions 17

6. Recommendations and Future Directions 17

7. Acknowledgement 18

8. References 19

Appendix

Technical Information Sources

1. The Defense Technical Information Center 26

2. National Technical Information Service 30

3. The Chemical Abstracts 35

4. The Engineering Index 36

5. Center for Fire Research, Fire Information Service 38

iii
-
FIRE CHARACTERISTICS OF COMPOSITE MATERIALS

A REVIEW OF THE LITERATURE

James E. Brown

Joseph J. Loftus

Richard A. Dipert

Abstract

A review is presented of the open literature concerning fire tests

of composite materials which may be considered for use in

U.S. Navy shipboard structures and installations. Results

obtained for thermoplastic resins, thermoset resins, and composite

structures are summarized from standard test methods. The methods

include tests for limiting oxygen index, smoke production, flame

spread, fire endurance, differential scanning calorimetry and

thermogravimetric analysis. Typical criteria used by various

investigators for ranking materials are discussed, and the

material rankings based on test results are given. Data from

non-standard tests designed to measure fire performance are also

discussed. A detailed review of data and results of tests for

selected references is given. Finally, recommendations are made

for test developments and for the future direction of the

U.S. Navy's fire evaluation program for composites and related

materials intended for shipboard use.

Key words: flame spread; fiberglass resins; hazard analysis; polymer

flammability; reinforced plastics; shipboard fires; thermoplastic resins;

thermoset resins.

1. Introduction

This report is part of a project to develop an improved capability for

predictive fire behavior of composite materials. The initial phase was to

conduct a review of the open literature for the Department of the Navy,

Naval Sea Systems Command (NAVSEA 05R25) , Washington, D.C., for organic

matrix composite materials. Composite materials are defined here as

combinations of two or more material components present as separate phases

and combined to form desired structures that take advantage of certain

1
properties of each component. The resin matrix may be a thermoplastic or

thermoset polymer; the reinforcement may be graphite, aramid, glass, or other

fiber. The Navy's overall objectives are the following:

1. Document information on the fire properties of composite materials.

2. Couple this information with results from small-scale (bench) fire

tests conducted by CFR on currently available composite materials.

3. Conduct large-scale fire tests for a broad range of composite

materials

.

4. Develop a predictive capability for material behavior in fullscale fire tests based on bench-scale tests.

While the Navy's end objectives are focused on the behavior of composites, it

was considered that attention had to be given to the properties of neat

resins, which are used as the matrices.

2. Technical Sources of Information

A computer search of five technical data bases was conducted for fire

information on composites and related materials. Table 1 lists these

2
sources, the total number of references found, and the number of references

found to contain fire information considered pertinent to the Navy's

interests

.

Table 1. Technical Information Sources

Total No. No. of References

of pertinent to

Re ferences Navy's interest

Defense Technical Information Center (DTIC)

National Technical Information Services (NTIS)

Engineering Index (El)

Chemical Abstracts* (CA)

Center for Fire Research Library

59 12

69 14

63 8

668 15

10 10

869 59

* 361 journal articles

42 conference reports

265 patents

The 59 references identified are cited in Section 8. Salient findings are

extracted and summarized in the appendix to this report.

2.1 Evaluation of Referenced Materials

Classification of the pertinent references cited in Table 1 showed that the

reports may be divided into three different categories, as shown in Tables 2,

3, and 4. Table 2 lists those references which contain fire information

obtained by standardized test methods and procedures. Table 3 lists those

references presenting data obtained by using non-standard fire tests designed

specifically to measure a particular fire property of a material. Table 4

identifies those references containing summations of data giving comparisons

3
or rankings of different composites and related materials based on fire

properties such as oxygen index, smoke, flame spread, and toxicity.

Table 2 - Standard Methods of Test

Sponsoring

organization

Procedure

Property Tested identification No. References

ASTM flame spread E 162 1,3,4,6,50

ASTM oxygen index flammability

test

D 2863 1,4,5,7,19,30,42

53,54,57,58,59

ASTM smoke (NBS chamber) E 662 1,3,6,19,42,50,

52,57,58,59

ASTM 25 ft. tunnel -flame spread E 84 52,53

ASTM fire endurance test E 119 22,23,24

ASTM DSC (polymers) D 3417 19,42

ASTM TGA D 3850 19,42

Table 3. Specific Fire Tests

Test References

1/4 scale room test 2 heat release 3,14,17,58

toxicity 6,17,18,19,58

2000° F exposure test 8

lightning (spark test) 9

burn/blast 10,11

burner rig 15

ballistic test 21

heat aging, heat stability 44

melt temperature 19,42

anaerobic char 15,51

activation energy 20

4
Table 4. Data Summation Reports

References

Feasibility of using Kevlar* on shipboard 12

Development of thermally stable aircraft panels 13

Improved fiber retention by use of fillers in graphite fiber/ 16

resin matrix composites

New and improved resin systems 25

Prototype rigid polyimide components 26

High-char-yield epoxy curing agents 27

Fire dynamics of modern aircraft from a materials point of view 40

Relative fire resistance of select thermoplastic materials 42

Flame and smoke management in polyester resin systems 43

Overview, choosing FR resins over iso and other resins 45

GRP** panels - fire code requirements 46

Flammability or explosive hazards of GRP 47

Survey tests for self -extinguishing and slow burning plastics 48

Effects of fiber glass reinforcement on flammability properties 49

of thermoplastics

A proposed rating system to describe the behavior of reinforced 50

plastics in large scale fire tests

Processing and flammability parameters of bismaleimide and some 51

other thermally stable resin matrices for composites

Fire performance of glass reinforced polyesters 53

Flammability and smoke measurements on glass reinforced 54

polyester resins

Summary, high toughness resins, high modules design 56

optimization, quality control, failure criteria for composites

Graphite composites with advanced resin matrices 57

5
Table 4. Data Summation Reports - continued

References

Thermal response of composite panels 58

Thermochemical characterization of some thermally stable 59

thermoplastic and thermoset polymers

* The use of tradenames does not constitute an endorsement of the product by

the National Bureau of Standards

** glass reinforced plastic

3. Criteria for Evaluation of Composite Materials

3.1 General Criteria for Choice of Resins

Fire performance is just one of the many criteria involved in the choice of

resins used in composites. Cost, mechanical properties, chemical and

thermal resistance, and ease of processing must also be considered. Given

below are some of the strong and weak characteristics for the two major

classes of resins.

Thermoplastics - Generic types: nylons, polystyrenes, polyethylenes

,

polycarbonates, polysulfones , polypropylenes, and

styrene/acrylonitriles

advantages - can be easily made with processing time limited

only to heating, shaping, and cooling the structure.

Can be salvaged and reworked.

6
disadvantages - shrinkage and creep problems, low resistance to

organic solvents, and low thermal resistance.

Thermosets - Generic types: epoxies, polyesters, imides, amide- imides

,

imidazoles

advantages - wide range of formulations, high temperature

capabilities, good solvent resistance, good mechanical and

electrical properties.

disadvantages - exothermic reactions during curing, shrinkage,

evolution of volatiles.

3.2 Criteria for Ranking Composites for Fire Resistance

Many criteria have been used by various investigators for rating and ranking

composite materials for fire performance. Phenomena most frequently

considered are:

1. Flammability

a. ability to withstand high radiant energy

b. high ignition temperature

c. low flame spread rate

d. low rate of heat release/fuel evolution/fuel contribution

e. ease of extinguishment

f. no violent reaction in proximity to heat or ignition source

2 . Smoke

a. high evolution temperature

b. low optical obscuration;

c. low soot conversion fraction

7
3.

Toxicity

a. high evolution temperature for toxicant

b. low rate of toxic gas released

c. low toxicity of gases

3 . 3 Findings from the Literature

It is beyond the scope of this report to list all the fire data from each of

the referenced materials listed in the Appendix; however, an attempt will be

made here to highlight results provided by some of the more thorough

investigations. Kourtides et al . [59] used standard fire tests, e.g., oxygen

index, flame spread, smoke evolution, etc. to develop rankings for thermoplastic and thermoset resins. Table 5 lists a relative fire resistance

ranking for 13 materials as indicated by oxygen index.

Table 5. Ranking by Limiting Oxygen Index for Polymers and Composites

LOI at 23°C

Thermoplastic resins

1. Acrylonitrile -butadiene -styrene 34

2. Polyaryl sulfone (PAS) 36

3. Polyether sulfone (PES) 40

4. 9,9 Bis - (4-hydroxyphenyl) fluorene/polycarbonate- 47

poly (dimethyl siloxane) block polymer (BPFC-DMS)

5. Polyphenylene sulfide (PPS) 50

Thermoset resins

1. Epoxy 23

8
Table 5. Ranking by Limiting Oxygen Index for Polymers

and Composites - continued

LOI at 23 °C

2. Phenolic 25

3. Polyaromatic melamine 30

4. Bismaleimide 35

Thermoset Composites

1. 40% epoxy/181 glass cloth 27

2. 40% phenolic/181 glass cloth 57

3. 40% polyaromatic melamine/181 glass cloth 42

4. 40% Bismaleimide/181 glass cloth 60

As indicated in Table 5 the bismaleimide was the best performer among the

thermosets tested while the polyphenylene sulfide was best among the thermoplastics .

Kourtides et al. [58] reported the use of oxygen index, smoke, and heat

release tests to determine the fire properties of sandwich panels used for

partitions and walls. (A sandwich panel here means a honeycomb core material

covered on both surfaces with a composite panel material.) Table 6 gives

rankings (1 - best, 4 - worst) for the materials based on an analysis of the

data presented in the report.

9
Table 6 . Order of Ranking of Sandwich Panels by Three Test Methods

Systems

NBS Smoke

chamber

Oxygen

Index

Heat Release Ratei

(OSU** Apparatus)

25 kW/my 50 kW/my

Epoxy 3 1* 4 4

Polyimide 1 2 3 1

Bismaleimide 2 1* 2 3

Modified Phenolic - - 1 2 Phenolic 4 1* - -

* All had the same LOI value

** Ohio State University

Not Tested

Based on the results in Table 6, Kourtides concluded the overall ranking in

decreasing order of fire resistance was:

Phenolic

Polyimide

Bismaleimide

Epoxy

Kourtides [57] also conducted oxygen index and smoke tests on graphite

composites and, based on these measurements, ranked the materials

accordingly, as given in Table 7.

Table 7. LOI and Smoke Ranking of Graphite Composites

Composites LOI (%) Smoke Ranking

Epoxy

Phenolic -Xylok*

Bismaleimide A

Phenol ic-Novolac*

Polyether sulfone

Polyphenyl sulfone

* The use of tradenames does not cons

the National Bureau of Standards.

41 5 46 6 47 4

50 1 54 3 52 2

an endorsement of the product by

10
The author also considered mechanical properties in developing an overall

ranking for the materials and concluded that:

The phenolic -xylok composite retained its mechanical properties at

elevated temperatures where the other resins failed. However, it

showed lower mechanical properties at ambient temperatures than the

epoxy composites.

The epoxy composite demonstrated the lowest fire resistance properties

of all the composites tested as described by LOI

.

The phenolic -novolac , polyether sulfone, and polyphenyl sulfone

composites exhibited both high oxygen index and low smoke evolution.

Composites made with bismaleimide A exhibited excellent fire resistance

properties, low moisture absorption, and excellent ambient temperature

mechanical properties. This resin is designed primarily for use as a

fire resistant, high char yield resin.

Gilwee et al. [29] ranked thermosetting resin samples according to char yield

and oxygen index, as shown in Table 8.

11
Table 8. LOI and Char Yield of Thermosetting Resins

Char yield (9 800 o C LOI (%)

Resin % Room temp. 100°C 200°C 300°i

Benzyl 63 43 36 32 31

Melamine 58 27 26 25 21

Phenolic 54 25 23 19 13

Polyimide I 53 27 26 23 19

Epoxy 10 23 22 18 12

It was concluded that:

The LOI of thermosetting resins can be estimated from the char yield as

determined by TGA in nitrogen. The LOI values decreased with

increasing temperature. The elevated temperature LOI tests provided a

convenient and reliable laboratory procedure to give information on the

potential flammability behavior of materials.

Ballard et al. [55] conducted radiant panel pyrolysis tests on an

epoxy/carbon fiber composite at 25 kW/m2 in a closed system. Non- flaming and

flaming modes produced different gas and aerosol compositions and had

different toxic effects. Non- flaming modes produced large quantities of

organic aerosols and carbon monoxide. These quantities were not lethal but

could hinder escape and may produce long-term toxic effects. The flaming

conditions produced hydrogen cyanide in addition to other toxic products.

12
Manley and Sidebotham [54] provided information on the relation of glass

fiber orientation (in two resin types, isophthalate and bisphenol) to LOI and

smoke measurement. Several systems were evaluated and are listed in Table 9:

Table 9 . Fiber Orientation in Composites

LOI (%)

Resin

Glass Used Resin Percent Fiber Orientation Isophthalate Bisphenol

none 100 18.8 19.3

chopped strand mat 74.4 random 19.6 19.7

spray 70.4 random 19.7 19.6

parallel wind 55.7 parallel 20.5 21.1

parallel wind 55.7 perpendicular 19.5 20.6

woven roving 48.3 parallel 21.0 20.7

helical wind 31.7 perpendicular 23.6 22.3

helical wind 31.7 parallel 20.9 21.5

The author found that the LOI values rose linearly as the proportion of fiber

increased. Parallel wound fibers had a higher LOI than perpendicularly wound

fibers. Smoke results were more variable and did not show any difference

attributable to the orientation of the fibers. Specimens cut perpendicular

to the direction of the fiber were more flammable and easier to ignite than

specimens cut parallel to the direction of the fiber. This difference was

related to the extent by which the exposed fibers trap the char.

Isophthalate resin is more flammable than the bisphenol; samples of

isophthalate containing less than 50 percent glass fiber will continue to

burn freely in ambient air at room temperature. The bisphenol resin produced

more smoke than the isophthalate.

Selley and Voccarella [52] investigated controlling flammability and smoke

emissions of reinforced polyesters. Glass reinforced laminates measuring 1/8

inch thick containing 30 percent glass were tested in accordance with the

13
ASTM E 84 tunnel test, the ASTM E 162 radiant panel test (flame spread) and

the smoke density chamber test, ASTM E 662. Results of tests on three sets

of material are listed in Table 10.

Table 10. Results of Tests on Reinforced Polyesters

System*

Test Method

and Propertv I II IV

ASTM E 162 flame spread index 75 7 7

ASTM E 84 flame spread 64 23 25

smoke emission 608 270 268

ASTM E 662 (Smoke Chamber)

Flaming Mode

maximum specific optical density 203 433 264

specific optical density at 90 s 2.5 18 11

specific optical density at 240 s 162 245 128

Non- flaming mode

maximum specific optical density 481 400 350

specific optical density at 90 s 1 1 5

specific optical density at 240 s 16 45 50

* System I - Orthophthalate resin with high alumina trihydrate filler

levels

System II - High performance fire retardant system used widely in

construction and transportation applications

System IV - A Het acid*/based resin developed specifically for use with

patented char- forming agent Fe2 0 3

.

* The use of tradenames does not constitute an endorsement of the product by

the National Bureau of Standards

From these and other data it was concluded that systems II and IV met Class I

flammability requirements in the tunnel test, having flame spread indices of

25 or less. Selley stated that the fuel contributions of both systems was

14
negligible while smoke emission was less than half that registered by the

filled orthophthalate system I.

A comparison of smoke density chamber data showed lower specific optical

density from the orthophthalic resin in both the flaming and non- flaming

modes than was registered by the conventional fire retardant system II.

System IV shows a significant reduction and had the lowest smoke emission

characteristics of the three systems. The combination of low flame spread

(class I) and low smoke emissions by both the E 84 and E 162 tests qualified

system IV for use under Urban Mass Transit Authority (UMTA, DOT) and HUD

proposed specifications. No consideration was given to toxicity effects in

this investigation.

Park [50] proposed a fire safety rating system for use with fiberglass

reinforced plastics (FRP) that would make use of flame spread, smoke development and toxicity measurements. Flame spread would be determined by the

E 84 tunnel test and the Factory Mutual Research Corp. room-corner test or

Underwriters Laboratory (UL) test method "Flammability Studies of Cellular

Plastics and Other Building Materials Used for Interior Finishes". Smoke

would be measured by the E 84 smoke developed index and toxicity would be

derived from the lethal concentration LC50 value as determined by the Alarie

thermal decomposition method [61]

.

In general, an industry trend is to have multiple tests rather than one

specific test which cannot define the total behavior of a material in a

15
fire. This is typified by the recommendations by Kourtides and Parker [42]

for using a combination of limiting oxygen index, smoke evolution, and

toxicity measurements to determine the relative fire resistance of some

thermoplastic materials, as shown in Table 11.

Table 11. LOI . Smoke & Toxicity Ranking of Thermoplastic Resins

Polymer Relative Fire

Resistance

Polyphenylene Oxide low

Acrylonitrile Butadiene Styrene

Bisphenol A Polycarbonate ( fire retardant )

Chlorinated Polyvinyl Chloride

Bisphenol A Polycarbonate ( non- fire retardant )

Polyarylsulfone

Polyvinyl idene Fluoride

Polyvinyl Fluoride

Polyether Sulfone

9,9 Bis (4-Hydroxyphenyl) Fluorene

Polycarbonate -Poly (Dimethylsiloxane)

Polyphenylene Sulfide high

4 . Summary

From 668 references on composite materials, a total of 59 were found to

contain fire information on materials pertinent to the Navy's interests. The

leading or most used tests were the limiting oxygen index test (ASTM E 2863),

16
che smoke density chamber test (ASTM E 662), and the flame spread test (ASTM

E 162). The general consensus among the references surveyed was that, among

the thermoset materials, bismaleimide and phenolic matrices were among the

best performers in the bench-scale fire tests and that epoxies were among the

lowest ranking. Polyphenylene sulfide performed well among the thermoplastic

materials tested.

5. Conclusions

Results of this survey clearly indicate that investigators primarily

limited their evaluation of composites to common small scale or bench type

fire tests. While results of these small scale tests are informative and

useful for exploratory purposes, we conclude that results from such tests can

be misleading without full-scale test studies to validate them. Validated

procedures for testing potential shipboard composites are not yet available

in the open literature. The majority of the tests cited are known to be poor

predictors of full-scale performance in other applications. Thus, it will be

necessary to focus only on those bench- scale tests which have been seen to

lead to successful full-scale fire predictions in existing applications, such

as rate of heat release.

6. Recommendations and Future Directions

Based on project studies so far, CFR recommends to NAVSEA that candidate

composite materials proposed for shipboard use be first evaluated by the new,

promising bench-scale test method, the cone calorimeter [60]. Measurements

17
with this test procedure have been shown to correlate well to full-scale

results in several applications [62]. The properties examined should include

heat release rate and smoke measurement, along with data on ignitability

.

Promising materials can then be selected. In the next phase, NAVSEA will

develop suitable design fire scenarios and criteria. CFR will then formulate

an appropriate program for full-scale testing. These full-scale tests are

envisioned to be mockups or sectional mockups of the appropriate shipboard

fire scenarios. When completed, the full-scale tests will not only serve to

evaluate the initial material choices, but will also validate the bench-scale

test protocol and permit most future testing pertinent to these scenarios to

be done in bench- scale.

7 . Acknowledgement

This study was supported in part by and was performed as part of a Naval Sea

Systems Command Special Forces Program on Composites for Ship Applications.

The NAVSEA point of contact was Mr. Charles F. Zanis (Sea 05R25) . Technical

support was furnished by Messrs. T. F. White and W. Dunham, Naval Sea Systems

Command, and Mr. J. G. Morris, David Taylor Naval Ship Research and

Development Center. The contract was administered by the Naval Research

Laboratory; Dr. Irvin Wolock was the Technical Monitor.

18
8 . References

The Defense Technical Information Center (DTIC)

(1) Technical Report

1980 Materials Characterization Test Program. ASTM Flammability and

Fire Shielding Tests for Candidate Kevlar -Reinforced (KRP) Armor

for the DDG933 Class of Ships, Naval Surface Veapon Center,

Dahlgren, VA

AD-B051321L

(2) Smith, B. D.

;

1982 Materials Characterization Program; Quarter-Scale Fire Tests;

Kevlar Heat Stress Panel Integrity Tests, Naval Surface Weapon

Center, Dahlgren, VA

AD-B069630L

(3) Smith, B. D. , Garrison, J.M.;

1981 Flammability and Potential Heat Release for Kevlar -Reinforced

Plastic (KRP) for Armored Radomes, Waveguides and Cable Guides,

Naval Surface Weapons Center, Dahlgren, VA

AD-B061000L

(4) Silvergleit, M. ; Morris, J.G.; LaRosa, C.N.

;

1977 Flammability Characteristics of Fiber -Reinforced Matrix

Composites, David Taylor Naval Ship Research and Development

Center Annapolis, MD, Materials Dept.

AD-B-019020L

(5) Macaione, D.P.; Dowling, R.P.; Bergquist, P.R.

;

1983 Flammability Characteristics of Some Epoxy Resins and Composites,

Army Materials and Mechanics Research Center, Watertown, MA

AD-A135282

(6) Wilhelmi , G.F.;

1975 Glass Reinforced Plastic Piping Systems for 2000 Ton Surface

Effect Ship, David Taylor Naval Ship Research and Development

Center, Bethesda, MD

AD-B034147L

(7) Technical Memo

1967 Flame Resistance Properties of GRP and Wood. Technical Program

on GRP for Large Boat Construction, Naval Applied Science

Laboratory, Brooklyn, NY

AD900022L

(8) Diepembrock, J.;

1973 Polyimide Fiberglass Composites Fireproof Tests, Boeing Co. - Wichita Div. - Wichita, KS

AD-B003786L

19
(9) Olson, G.O.; Force, R.D., Lanba, J.T.;

1980 Ignition Hazard Study of Advanced Composite Free Tank, Boeing

Military Airplane Co., Seattle, WA

AD-B048459L

(10) Musselman, K.A.

,

Babinsky, T.C.;

1979 Burn/Blast Test for Boron- Tungsten Composites, Naval Surface

Weapons Center, Dahlgren, VA

AD-B044568L

(11) Babinsky, T.C., Musselman, K.A;

1978

Burn/Blast Test of Aircraft Structural Elements, Naval Surface

Weapons Center, Dahlgren, VA

AD-B033711L

(12) Smith, B. D.; Mannschneck, W.A. ; Crider, J.F.; Mullelman, K.A.

1977 The Feasibility of Kevlar Composite Armor for Protection of Naval

Ships, Naval Surface Weapons Center, Dahlgren, VA

AD-C009625L

The National Technical Information Services (NTIS)

(13) Arnold, D.B.; Burnside, J.V.; Hajari, J.V.;

1976 Development of Lightweight Fire Retardant, Low Smoke, High

Strength, Thermally Stable Aircraft Floor Paneling, Boeing

Commercial Airplane Co., Seattle, WA

N76-24365/8

(14) Bowles, K.J.

1980 Fire Test Method for Graphite Fiber Reinforced Plastics, NASA - Lewis Research Center

N80-18107/6

(15) Cavano , P. J .

;

1979 Second Generation PMR Polyimide/Fiber Composites, TRW Equipment

Laboratories, Cleveland, OH

N80- 12118/9

(16) Gluyas, R. E.; Bowles, K. J.;

1980 Improved Fiber Retention by the Use of Fillers in Graphite

Fiber/Resin Matrix Composites, NASA - Lewis Research Center

N80- 13171/7

20
(17) Kanakia, M.D. , Switzer, W.G. ; Hartzell, G.E.; Kaplan, H.L.

;

1980 Fire Test Methodology for Aerospace Materials. 1: Thermal and

Smoke Toxicological Assessment of Graphite/Bismaleimide and

Graphite/Epoxy Systems, Southwest Research Institute - Dept, of

Fire Technology, San Antonio, TX

N81-26185/1

(18) Kourtides, D. A.

1983 Fire Resistant Films for Aircraft Applications, NASA - Ames

Research Center, Moffett Field, CA

N83-22320/6

(19) Kourtides, D.A.

;

Parker, J. A., Hilado, C.J.

1976 Thermoplastic Polymers and Improved Fire Safety, NASA - Ames

Research Center, Moffett Field, CA

N77-14206/5

(20) Kubin, R.F.

1979 Thermal Characteristics of 3501-6/AS and 5208/T300 Graphite Epoxy

Composites, Naval Weapons Center, China Lake, CA

AD-AG71067/3

(21) Schlitz , R.J.

1980 Investigation of the Structural Degradation and Personnel Hazards

Resulting from Helicopter Composite Structures Exposed to Fires

and/or Explosions, Bell Helicopter, Textron, Fort Worth, TX

AD-A104757/0

(22) Son, Byung Chan

1973 Fire Endurance Test of a Fiber Glass Reinforced Polyester Double

Wall Assembly, National Bureau of Standards, Washington, DC

PB-221184/5

(23) Son, Byung Chan

1972 Fire Endurance Test of a Fiberglass Reinforced Polyester Resin

Wall Assembly, National Bureau of Standards, Washington, DC

PB-214784/1

(24) Williamson, R.B.; Baron, F.M.

1971 Fire Test of Fiberglass Reinforced Plastic Structural Wall Panel,

University of California at Berkeley - Structural Engineering

Laboratory, Berkeley, CA

PB- 222900/3

(25) Wolock, I. 1973 Conference Report on New and Improved Resin Systems

Office of Naval Research, London

AD-780485/9

21
?

(26) Wykes, D.H.

1975 Prototype Rigid Polyimide Components, Rockwell International

Corp. - Space Division, Downey, CA

AD-780485/9

(27) 1981 High-Char-Yield Epoxy Curing Agents, National Aeronautics and

Space Administration, Washington, DC

PB81-971049

Chemical Abstracts (CA)

(28)

Hecht , J.L.

1982 New Flame -retarded Glass Reinforced Polyethylene Terephthalate

Resins, Plastics Technology, Vol.18, No.l, pp. 109-122

(29) Gilwee, W.J.; Parker, J.A.; Koutides, D.A.

1980 Oxygen Index Tests of Thermosetting Resins .Journal of Fire and

Flammability, Vol.II, No.l, pp . 22-31

(30) Parvin, K.

;

1979 Fire Performance of Glass Reinforced Polyesters, Fire and

Materials, Vol.3, No. 4, pp. 218-222

(31) Gagliani, J., Lee, R. ; Sorathia, U.A.K. ; Wilcoxson, A.L.

1980 Development of Fire-Resistant, Low Smoke Generating, Thermally

Stable End Items for Commercial Aircraft and Spacecraft Using

Basic Polyimide Resin, NASA (Contract Rep) -CR- 160576

,

SR79-R04674-38 , p. 176

(32) Gilwee, W.J. et al

.

1976 Fire Resistant Low Density Composites - High Performance

Plastics, National Technical Conference, Soc. Plast. Eng.,

Vol. 43, p. 6

(33) Watanable, T. ; Soto, M. ; Kumagima, H.

1982 High Current DC Arc Ignition Testing of Glass Reinforced Plastics

Composites Vol. 13 No. 1; pp . 24-28

(34) Haines, P.J.; Leven, T.J.; Skinner, G.A.

1982 A Study of Flame Retarded Polymers by Thermal Methods

Thermochem. Vol. 59 No. 3, pp . 331-342

(35) Chanilik, B.V.

1979 Chemical Resistant Flame Retardant FRP

Aust. Plast. Rubber, Vol. 30-31 N: 12-1, Page 11

22
(36) Dean, T.C.; Johnson, D.B.; Cooper, F. 1977 The Use of Antimony Trioxide in Flame -retardant Glass-reinforced

Polyester for the Boat-building and Construction Industries

Plastic and Rubber Mater. Appl. Vol. 2 No. 2, pp. 71-76

(37) Schaper, K.L.

1981 Toxicity of Fiberglass Reinforced Plastics

Build Contents-Real Fire Probl., Fall Conf.

Fire Retardant Chemical Assoc, pp. 53-62

(38) Kumar, D.; Faklen, G.M.; Parker, J.A.

1984 High-strength Fire and Heat-resistant Imide Resins Containing

Cyclotriphosphazene and Hexafluoroisopropylidene Groups

Polymer Sci.; Polym. Chem. Ed. Vol. 22 No. 4, pp. 927-943

(39) Amembol, A.

1976 Fire Retardant Analysis of an FRP Composite Before and After the

Tunnel Test

J. Fire Retard. Chem. Vol. 3 No.l, pp. 22-33

(40) Parker, J.A.; Kourtides, D.A. ; Fisk,R.H. ; Gilwee, W.J.

1983 New Fireworthy Composites for Use in Transportation Vehicles

Fire Sciences, Vol. 1, pp. 432-458

(41) Theberga, J.E.

1972 Flammability Resistance of Glass Fortified Thermoplastic Resins

Soc. Plast. Eng., S. Calif. Sect, March 27, pp. VIII, 1 & 5

The Engineering Index

(42) Kourtides, D.A. ; Parker, J.A.

1978 The Relative Fire Resistance of Select Thermoplastic Materials

Plastics Design and Processing, Vol. 18, No. 4, pp. 53-63

(43) Keating, J.Z.,

1977 Flame and Smoke Management in Polyester Resin Systems

Reinf. Plast. Compos. Inst.,

32nd. Ann. Conf. Proc.

SPI, New York, NY, Sect. 13-F, p. 7

(44) Turpock, H.S., McQuarrie, T.S.; Chan, R.M.

;

Gunderson, K.W.

1977 High Temperature Properties of Fire Retardant and Corrosion

Resistant FRP

Reinf. Plast. Compos. Inst.,

32nd. Ann. Conf. Proc.

SPI, New York, NY, Sect. 5-C, p. 15

23
(45) Trampenau, R.H.; Wilson, T.B.

1975 Use of Fire Retardant Polyester in Willard Boat Works 120 Foot

Motor Vessel

Reinf. Plast. Compos. Inst.,

30th. Ann. Conf. Proc.

SPI, New York, NY, Sect. 2-E, p. 7

(46) Trampenau, R.H. ; Fire Retardant FRP in Construction

SPE, Annu. Tech. Conf., 31st, Pap, Montreal, Que., pp. 680-684

(47) Fuller, R.B. ; Jensen, J.D.

1973 Plastic Fiber Glass Operations

Fire Technol, Vol. 9, No. 2, May 1973, pp. 101-111

(48) Baron, A.L.; Fried, W.T.

;

McNally, D. 1972 Self -Extinguishing Celanex - A Remarkable New High Performance

Engineering Thermoplastic

SPE, Reg. Tech. Conf. (Advances in Reinforced Thermoplastics),

Tech paper for meet (Calif. Sect), March 27, 1972, Session IX,

pp. 15-421; 817

(49) Hattori, K.

1969 Effects of Fiber Glass Reinforcement on Flammability Properties

of Thermoplastics

SPE, Reg Tech Conf, Tech pap (Western New England Sec) pages 9-13

421: 817

(50) Park, R. E. 1983 A Proposed Rating System to Describe the Behavior of Reinforced

Plastics in Large Scale Fire Tests

ASTM STP 816 E. L. Schaffer, Ed.

,

American Society for Testing

and Materials, 1983, pp . 107-113

(51) Kourtides, D. A.

1984 Processing and Flammability Parameters of Bismaleimide and Some

Other Thermally Stable Resin Matrices for Composites

Polymer Composites, Vol. 5, No. 2, pp. 143-150

(52) Selley, J.E., and Voccarella, P. W.

1979 Controlling Flammability and Smoke Emissions in Reinforced

Polyesters

Plastics Engineering, Vol. XXXV, No. 2, pp. 43-47

(53) Parvin, K. 1979 Fire performance of Glass Reinforced Polyesters

Interflam 79, Guildford, UK, March 1979

(54) Manley, T.R., and Sidebotham, S. 1977 Flammability and Smoke Measurements on Glass Reinforced Polyester

Resins

Fire Research, Vol. 1, No. 2, pp. 97-100

24
(55) Ballard, R. et al

.

1980 Radiant Panel Tests on Epoxy/Carbon Fiber Composites

NASA Technical Memorandum 81185

(56) Poranski, C.F.

1984 High Performance Composites and Adhesives for V/STOL Aircraft NRL

memorandum report 5231

(57) Kourtides, D. A.

1980 Graphite Composites with Advanced Resin Matrices

AIAA/ASME/ASCE/AHS 21st Structures, Structural Dynamics and

Materials Conference, May 12-14, 1980, Seattle, WA

(58) Kourtides, D.A. et al.

1979 Thermal Response of Composite Panels

Polymer Engineering and Science

Vol . 19, No. 3, pp. 226-231

(59) Kourtides, D.A. et al

.

1979 Thermochemical Characterization of Some Thermally Stable

Thermoplastic and Thermoset Polymers

Polymer Engineering and Science

Vol. 19, No. 1, pp. 24-29

(60) Babrauskas , V.

1982 Development of the Cone Calorimeter -- A Bench- Scale Heat Release

Rate Apparatus Based on Oxygen Consumption

National Bureau of Standards

Washington, D.C.

NBSIR 82-2611

(61) Alarie, Y.

1981 Toxicity of Thermal Decomposition Products: An Attempt to

Correlate Results Obtained in Small Scale and Large Scale Tests

Journal of Combustion Toxicology

Vol. 8, Feb. 1981, pp. 58-68.

(62) Babrauskas, V.

1984 Bench-Scale Methods for Prediction of Full-Scale Fire Behavior of

Furnishings and Wall Linings. Society of the Fire Prot. Engrs

.

Report 84-10, Boston.

25
APPENDIX

Technical Information Sources

I . The Defense Technical Information Center (DTIO

Three reports from the Naval Surface Weapons Center, Dahlgren, VA, deal with

Kevlar poly (p-phenylene terephthalate) reinforced plastics (KRP) . The first

technical report [1] presented fire and flammability test data for three new

flexible Kevlar-reinforced plastic (KRP) armors. All three exceeded

requirements of MIL-STD-1623B and NAVSEA guidelines with respect to flame

spread index, oxygen index and smoke obscuration index- -two of them

significantly. A conservative 200°C (392°F) maximum service temperature for

the KRP insulation interface was recommended for new armors.

In a second report, Smith [2] presents results of quarter- scale fire tests

and Kevlar heat- stress panel integrity tests for evaluating flexible KRP.

The objective of the tests was to determine the level of protection from

fragments, flammability characteristics, resistance to environmental

vibration and shock stress of mockup assemblies, and shipyard safety

requirements with respect to applying the adhesive, cutting and trimming the

KRP panels and cost to install the armor on board ship.

In the third report, Smith and Garrison [3] describe standard flammability

and potential heat release tests performed on several new KRP armors

developed for radomes ; their performance was compared to that obtained for

26
early KRP armors. Rigid KRP armor fabricated using polyester resins was

recommended for rigid self-supporting, compound curved surface armored

radomes

.

Silvergleit et al . [4] from the David Taylor Naval Ship Research and

Development Center, Annapolis, MD, Materials Department, provide results of

tests to determine the flammability characteristics of fiber reinforced

organic matrix composites, in which the effects of resin, fiber, and fire

retardant additives on flammability were evaluated. Information is presented

on flame spread index determined by the radiant panel test, the amount of

smoke generated and products of combustion based on the smoke density chamber

and the amount of oxygen required to support combustion according to the

limiting oxygen index method. Polyimide composites were the most resistant

to flame spread and exhibited the lowest evolution of smoke and toxic

products. No significant differences in flammability characteristics were

observed for the loose polyester and epoxy glass cloth laminates. The

addition of antimony trioxide and hydrated alumina to the polyester and epoxy

resin systems significantly decreased flammability characteristics but caused

a marked increase in smoke evolution. It also was observed that smoke

properties were dependent on resin content, while the type of reinforcement

did not appear to affect flame spread index or smoke properties. The use of

protective barriers or intumescent coatings in selected shipboard areas was

suggested to reduce flame spread and length of time for generation of smoke.

27
Macaione et al. [5] from Army Materials and Mechanics Research Center,

Watertown, MA, determined the flammability characteristics of a number of

epoxy resin formulations and glass fiber reinforced epoxy resin composites.

These were evaluated by thermal analysis, limiting oxygen index/temperature

index, flash ignition, and smoke density measurement techniques. Results

indicated that appropriate flame retardant additives or halogenated monomers

should be incorporated into the matrix resin to increase material

survivability and reduce resin combustibility.

Wilhelmi [6] from the David Taylor Naval Ship Research and Development

Center, Bethesda, MD, tested glass reinforced plastic piping systems for 2000

ton surface effect ships. Experiments were conducted with commercially

available glass reinforced plastic piping material in the areas of surface

flammability; smoke density and toxicity; fire performance under dry,

stagnant, and flowing water conditions.

The Naval Applied Science Lab, Brooklyn, NY, in a technical memorandum [7],

reported on the flame resistance properties of GRP and wood in a

technical study on glass reinforced plastics (GRP) for large boat

construction. A FRP laminate fabricated with a fire retardant resin was

somewhat lower in ignition time than equivalent material made with general

purpose resin but the latter material burned five times longer than the fire

resistant type. Soaking in diesel fuel had very little effect on the FRP

materials, absorption was minimal, and flame resistance properties were

unaffected.

28
Diepembrock [8] of the Boeing Co., Wichita Division, made a 2000°F (1092°C)

fire test on two polyimide-glass fiber panels consisting of six and 12 plies

of structural backing, that had been sealed with polyimide adhesives and six

ply acoustical facing. The test structure simulated the inner wall of the

fan duct assembly on the FAA/JT30 ground test demonstration nacelle.

Olson et al. [9] from the Boeing Military Airplane Co., Seattle, WA, assessed

the ignition hazard of an advanced composite fuel tank. The report presents

results of a program to assess the fuel ignition vulnerability of a glass

reinforced-epoxy composite wing box in a lightning environment. Concern was

with ignition of the GR/EP fabric and tape, fuel fitting to bulkhead

sparking, and jointed panel sparking.

Mullelman and Babinsky [10] at the Naval Surface Weapons Center, Dahlgren,

VA, conducted burn/blast tests to determine if fibers would be released from

boron/tungsten/epoxy laminates. It was found that five percent by weight of

free fibers were produced. Burn times of 20 minutes resulted in 20 to 21

percent weight loss.

The same Navy personnel [11] also investigated the effects of fire and

explosion on carbon/graphite composite materials used in aircraft structural

elements. Tests were conducted in a totally enclosed 244 cubic meter

compartment so that all released material could be captured and its

dissemination characteristics ascertained.

29
Lastly, Smith et al. [12] of the Naval Surface Weapons Center, Dahlgren, VA,

determined the feasibility of Kevlar composite armor for protection of Naval

ships. This is a confidential report, but distribution can be made to U.S.

Government agencies.

II . National Technical Information Services (NTIS)

Of a total of sixty references found in the National Technical Information

Services (NTIS) , twenty- two dealt with problems associated with the release

of graphite fibers from the composite matrix. A total of seven references

were considered pertinent to the Navy's fire interests and these will be

discussed here.

Arnold et al . [13] of Boeing Commercial Airplane Co., Seattle, WA, discussed

fire resistance and mechanical property tests on sandwich configurations

composed of resin-glass fiber laminates bonded with adhesives to Nomex

honeycomb cores. Tests were designed to establish whether fire safety of an

airplane could be improved without sacrificing mechanical performance of the

aircraft floor panels.

Bowles [14] of NASA-Lewis Research Center presented a test method for

assessing the burning characteristics of graphite fiber reinforced

* composites. The method utilizes a modified rate of heat release apparatus.

The application of the test to the assessment of composite materials is

illustrated for two resin matrix/graphite composite systems.

30
Cavano [15] of TRW Equipment Laboratories investigated isothermal aging of

graphite fiber, neat resin samples, and composite specimens in air at 326°

C

(600°F). Exposures at 65°C and 97 percent relative humidity were conducted

for both neat resin and composites for eight day periods. Anaerobic charring

of neat resin and fire testing of composites were conducted. The composites

were fire tested on a burner rig developed for the program. Results

indicated that neat Polymerization Monomeric Reactants (PMR-2) polyimide

matrix resins exhibited excellent isothermal resistance and that PMR-2

composite properties appear to be influenced by thermo -oxidation stability of

the reinforcing fiber.

Gluyas and Bowles [16] of NASA- Lewis Research Center tested a variety of

matrix fillers for their ability to prevent loss of fiber from graphite

fiber/PMR polyimide and graphite fiber/epoxy composites in a fire. Fillers

tested included powders of boron, boron carbide lime glass, lead glass, and

aluminum. Boron was most effective in preventing loss of graphite fiber

during burning. Mechanical properties of composites containing boron filler

were measured and compared to those of composites containing no filler.

Kanakia et al. [17] at the Southwest Research Institute made thermal and

toxicity tests and smoke assessments for graphite/bismaleimide and

graphite/epoxy systems. Both materials showed a high degree of thermal

stability, with total heat release values being essentially identical under

piloted ignition conditions over a range of 50 to 100 kW/m2 incident heat

flux. In every case the graphite/bismaleimide composite outperformed the

31
graphite/epoxy system, e.g., the graphite epoxy material auto-ignited at

about 70 kW/m2

, produced about 23 percent higher peak heat release rates,

approximately 42 percent more carbon monoxide, and considerably more smoke.

Toxicological potencies of smokes produced were also evaluated for 30 minute

exposures and were found to be comparable to wood.

Kourtides [18] at the NASA, Ames Research Center, reported on a study of

aircraft decorative films for flammability, smoke emission, toxic gas

emission, and flame spread. Candidate films were: flame modified polyvinyl

fluoride, polyvinylidene fluoride, polyimide, polyamide, polysulfone,

polyphenylsulfone , polyethersulfone , polybenzimidazole, polycarbonate,

polyparabanic acid, polyphosphazene , polyetheretherketone (PEEK), and

polyester. The films which exhibited the highest fire resistance properties

were of PEEK, aramide polyamide, and ISO-BPE polyester.

Kourtides et al. [19] also reported on the thermochemical and flammability

characteristics of typical thermoplastic materials. Properties studied

included melt temperature, enthalpy changes by DSC, TGA in anaerobic and

oxidative environments, oxygen index, smoke evaluation, relative toxicity of

the volatile products of pyrolysis, and selected physical properties.

Kubin [20] at the Naval Weapons Center China Lake, CA, reported thermal

characteristic data for two graphite epoxy composites intended for use as

aircraft structural components. Activation energies were found to be 19.7

and 25 kcal/mole, while the heats of reaction for pyrolysis were -18.4 and

-20.4 cal/g for the composite materials. The kinetic properties were used to

32
develop predictions of thermal degradation at flight temperatures. For fire

fighting purposes, it was recommended that bulk material temperature be

reduced well below 300° C (572°F) to prevent continuation of exothermal

pyrolysis reactions. It was also found that differential scanning calorimetry provided a more sensitive test of composite cure than reflectance

measurements

.

Schlitz [21] at Bell Helicopter Textron, Fort Worth, TX, reported on tests of

two helicopter structures: a sheet-stiffened, built-up door of Kevlar-49

fabrics impregnated with epoxy resin, and a honeycomb sandwich fuselage shell

structure of graphite/epoxy fabric skins on a Nomex honeycomb core. Tests

conducted on materials from these structures were smoke generation and

structural degradation tests. Ballistic tests on the complete test structure

were conducted to determine whether the structure would ignite under High

Energy Impact conditions. A major part of the paper was a literature survey.

Based on this survey and testing, design criteria for structural composite

components were investigated and, when appropriate, formulated.

Son [22] at the National Bureau of Standards conducted standard fire

endurance tests on glass fiber reinforced polyester double wall assemblies.

Each wall assembly contained glass fiber-reinforced (GRP) sheet faces glued

to a corrugated GRP stiffener core. The GRP core members were painted with

an intumescent type fire retardant paint and the core spaces were filled with

mineral wool insulation. The wall represented a party wall in single family

attached housing and was tested under an applied load of 700 lb per linear ft

per wall.

33
In another report, Son [23] reported on fire endurance tests of a glass fiber

reinforced polyester resin wall assembly with mineral wool fill. Under an

applied load of 730 lb per linear ft (plf) the wall was subjected to fire

tests in accordance with the ASTM E 119 Fire Endurance Test. The time for

failure, which occurred by flame- through of the assembly to the unexposed

surface, was approximately six minutes. Considerable smoke evolved

throughout the fire exposure period.

Williamson and Baron [24] at the University of California, Berkeley, CA,

described a fire test of glass fiber reinforced plastic structural wall

panels to determine the performance of a load-bearing glass fiber reinforced

polyester wall systems subjected to standard fire conditions in the ASTM

E 119. The structural composite was a glass fiber reinforced polyester

laminate manufactured from random oriented glass fibers and impregnated with

specially formulated polyester resins. The composite contained a large

percentage of inorganic fillers. The wall panel passed thermal requirements

for a 30 minute load-bearing fire rating.

Wolock [25] provided a conference report on new and improved resin systems.

Supported by the Reinforced Plastics Group of the Plastics Institute, the

meeting was held in London in 1973. Discussed were fluorinated epoxies,

vinyl esters, furanes , polyimides , Friedel-Crafts resins, rubber reinforced

resins, and fire retardant resins. In addition, developments in silane

coupling agents were discussed and one paper was presented on the effect of

water on carbon fiber-epoxy composites.

34
Wykes [26] at the Rockwell International Corporation, Downey, CA, provided

information on prototype rigid polyimide components. A brief history of

high- temperature polyimide resins is given along with a discussion of the

properties of DuPont PI 4701 glass laminates. Mechanical and flammability

properties of DuPont PI 2501/glass laminates are compared with epoxy,

phenolic, and silicone high temperature resin/glass material systems.

Off-gassing characteristics are also presented. A discussion is included on

the current developments in polyimide materials technology and the potential

civilian and government application of polyimide materials to reduce fire

hazards and increase the survivability of men and equipment.

A NASA report [27] discussed high char yield epoxy curing agents. Epoxy

resins are the most widely used matrix resins in graphite fiber reinforced

resin matrix composite materials because they are easy to process and have

excellent mechanical properties. When exposed to fire, these composites lose

their structural integrity and free graphite fibers are released. A novel

class of imide- amine curing agents has been synthesized, which more than

doubles the char yield of cured epoxy resins while preserving structural

integrity and preventing fiber release.

III. The Chemical Abstracts (CA)

A review of the Chemical Abstracts data base generated a total of 361 journal

articles, 33 technical reports, 42 conference reports, and 265 patents. From

all of these a total of 14 items were selected for their contribution to the

35
fire and flammability information. These items are numbered 28 to 41 in the

Reference listing. Complete abstracts, however, are not available in the

computer data base and thus only those reports judged to be highly pertinent

were selected and discussed in the text.

IV. The Engineering Index (El)

A survey of the Engineering Index (El) produced a total of 62 references.

Fifteen of these were considered pertinent to fire and flammability and of

these six were previously cited in the sections above.

Kourtides and Parker [42] studied the thermochemical and flammability

characteristics of some typical and advanced thermoplastic materials for use

in aircraft interiors. The properties studied were melt temperature,

enthalpy by DSC, TGA analyses in oxidative and anaerobic environments, oxygen

index, smoke evolution, relative toxicity of volatile products of pyrolysis,

and selected physical properties. Test results and relative rankings based

on some of the flammability, smoke and toxicity properties are presented.

Under these test conditions some of the advanced polymers evaluated were

significantly less flammable or toxic than polymers in current use.

Keating [43] described flame and smoke test methods used to determine the

relative flammability of polyester formulations. Several typical

formulations were checked by each method and the values are reported. The

economics of flame and smoke management are discussed and the effect of glass

contents, core materials, and methods of fabrication on test results is

36
covered. Heavy emphasis is placed on the use of hydrated alumina based

fillers and blended resins as the most cost effective tool to meet

flammability standards.

Turpock et al . [44] provided heat aging and heat stability data on glass

fiber reinforced plastics used in the construction of hoods, ducts, stacks,

and other structures. The heat aging data provided information on laminates

after continuous exposure to various elevated temperatures up to and

including one year in duration. The heat stability data provide information

about the physical strength retention of the polyester laminates at various

elevated temperatures.

Trampenau and Wilson [45] discussed Willard Boat Works experience with FR

resins and reasons for choosing these materials over the more conventional

ortho and isophthalate boat resins. The largest GRP boat built in the USA is

described. Engineering and technical aspects of constructing the 120 ft

vessel are described with special emphasis on innovation design features.

Resin and laminate properties, strength retention at elevated temperatures,

insulation values, and fire retardant properties are discussed. Work with

the American Bureau of Shipping on design criteria for this prototype of a

new vessel class is also presented.

Trampenau [46] also discussed the use of GRP panels in buildings in regard to

code requirements for flame retardance of building materials. Particular

attention was given to testing of reinforced polyester structural members as

well as to full scale testing of a two-story panel configuration. Special

37
resin development is also included in this report. Several case histories

are described and general conclusions are drawn as far as code approval is

concerned.

Fuller and Jensen [47] presented a literature review of plastic glass fiber

operations and deals specifically with the flammability or explosion hazards

of glass fiber reinforced plastics processing.

Baron et al. [48] described the properties, performance, and processing of

commercially available molding materials, flame retarded glass-reinforced

thermoplastic polyester and poly (butylene terephthalate) . Survey tests for

self extinguishing, corrosivity, physical, thermal, mechanical, and

electrical characteristics, as well as melt viscosity and processability,

showed no significant property difference between the standard slow burning

and self -extinguishing compositions.

Hattori [49] presented a study on the effects of glass fiber reinforcement on

the flammability properties of thermoplastics. Three tests to determine

flame retardance are described. Glass fiber reinforced plastics are compared

with unreinforced plastic materials, such as polycarbonate, polysulfone,

styrene-acrylonitrile copolymer, etc.

V . Center for Fire Research. Fire Research Information Services

Park [50] proposed a fire rating system for use with glass fiber reinforced

plastics in a paper that covers ignition, flame spread, smoke development,

38
and toxicity. The tests chosen for the rating system are described and

examples presented of how several different types of FRP sheet perform in

these tests. A new class of fire retardant systems was presented, offering a

combination of low flame spread, low smoke, and low toxicity. Toxicity data

are presented on both large-scale (room burns) and small-scale tests.

Kourtides [51] studied the effect of processing variables on the flammability

and mechanical properties of state of the art and advanced resin materials

for graphite composites. Resin matrices evaluated included state of the art

epoxy, phenolic novolac, phenolic -Xylok, two types of bismaleimides , benzyl

polyethersulfone , and polyphenylsulfone . Comparable flammability and

thermochemical data on graphite -reinforced laminates prepared with these

resin matrices are presented and the relationship of some of these properties

to the anaerobic char yield of the resins is described.

Selley and Voccarella [ 52 ] cited specific additives that can inhibit

flammability by promoting the production of char in the early stages of

burning. Flammability was characterized by the ASTM E 84 tunnel test, the

ASTM E 162 radiant panel test, and the ASTM E 662 smoke density chamber test,

all currently recognized test methods.

Parvin [53] from Great Britain discussed the fire performance of glass

reinforced polyesters as determined by simple strip burning tests, BS 476

tests, ASTM E 84 tunnel test, limiting oxygen index, and Australian AS 1530.

Results of tests on five different resins are presented.

39
Manley and Sidebotham [54], also of Great Britain, discussed flammability and

smoke measurements of glass reinforced polyester resins. The effects on

flammability and smoke production on the amount and orientation of glass

fiber in reinforced polyesters were studied by means of critical oxygen index

(COI) method (ASTM D 2863-70) and a smoke chamber test (Stanton FTB) . No

significant difference were found among resins, but the COI value rose

linearly as the proportion of fiber increased. Parallel wound fibers had a

higher COI than perpendicularly wound fibers. Smoke results were more

variable and did not show any differences attributable to the orientation of

the fibers.

Ballard et al. [55] used a radiant panel test chamber to study the effects of

pyrolysis of polymeric materials. The thermal response of the sample and

composition of gas and aerosol produced were determined. Toxicological

effects of the gas and aerosol in the chamber were determined by changes in

cardiac action, respiration, blood enzymes and delayed escape responses in

animals. Data were presented for pyrolysis of epoxy/carbon fiber composite

at 25 kW/m2

. Non- flaming and flaming modes produced different gas and

aerosol compositions and different toxic effects. Non-flaming modes produced

large quantities of organic aerosols and carbon monoxide. The flaming

condition produced hydrogen cyanide, in addition to other toxic products.

Poranski [56] presented a summary of reports designed to develop and

characterize high modulus, high toughness resins with use temperatures of 350

to 450°F or higher; to develop failure criteria for composite design optimization; and to establish appropriate quality control parameters.

40
Kourtides [57] reported on the effect of processing variables on the

flammability and mechanical properties of state of the art and advanced resin

matrices for graphite composites. Resin matrices included state of the art

epoxy, phenolic-novolac , polyethersulfone , and poly (p-phenylene sulfone)

.

Comparable flammability and thermochemical data on graphite-reinforced

laminates prepared with these resin matrices are presented and the

relationship of some of these properties to the anaerobic char yield of the

resins is described.

Kourtides et al. [58] provided information on the thermochemical and

flammability characteristics of laminating resins and composites. The high

temperature performance of laminating resins, such as modified phenolics,

polyimides, and bismaleimides , is compared with the performance of epoxies.

The relationship of increased fire safety with the use of polymers with high

anaerobic char yield is shown. Processing parameters of the state of the art

epoxy resin and advanced resin composites are detailed.

Kourtides et al. [59] studied the thermochemical and flammability properties

of some thermally stable polymers. These resins were primarily used in the

fabrication of glass reinforced prepregs . Test results and relative rankings

of some of the flammability parameters are presented and the relationship of

molecular structure, char yield, and flammability of the polymers are

discussed.

41
FORM NBS-1 14A (REV. 11 84) U.S. DEPT. OF COMM. 1. PUBLICATION OR 2. Performing Organ. Report No. 3. Publication Date BIBLIOGRAPHIC DATA

REPORT NO. SHEET (See instructions) NBSIR 85-3226 August 1986

4. TITLE AND SUBTITLE

FIRE CHARACTERISTICS OF COMPOSITE MATERIALS - A REVIEW OF THE LITERATURE

5. author(S) j ames £ Brown, Joseph J. Loftus, Richard A. Dipert

6. PERFORMING ORGANIZATION (If joint or other than NBS, see instructions) 7. Contract/Grant No.

NATIONAL BUREAU OF STANDARDS

U.S. DEPARTMENT OF COMMERCE 8. Type of Report & Period Covered

GAITHERSBURG, MD 20899

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, State, ZIP)

U. S. Department of the Navy

Naval Sea Systems Command (NAVSEA 05R25)

Washington, DC

10.

SUPPLEMENTARY NOTES

j Document describes a computer program; SF-185, FlPS Software Summary, is attached.

11.

ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bi bl iography or literature survey, mention it here) A review is presented of the open literature concerning fire tests of composite

materials which may be considered for use in U.S. Navy shipboard structures

and installations. Results obtained for thermoplastic resins, thermoset

resins, and composite structures are summarized from standard test methods.

The methods include tests for limiting oxygen index, smoke production, flame

spread, fire endurance, and also from measurements of polymer properties,

including differential scanning calorimetry and thermogravimetric analysis.

Typical criteria used by various investigators for ranking materials are discussed, and the material rankings based on test results are given. Data

from non-standard tests designed to measure fire performance are also

discussed. A detailed review of data and results of tests for selected

references is given. Finally, recommendations are made for test developments

and for the future direction of the U.S. Navy's fire evaluation program for

composites and related materials intended for shipboard use.

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) composite materials’, fire tests* flammability; fiberglass resins: reinforced

plastics: thermoplastic resins: thermosetting resins

13.

AVAILABILITY 14. NO. OF

PRINTED PAGES

[X

J Uni imited

| ) For Official Distribution. Do Not Release to NTIS

[ ) Order From Superintendent of Documents, U.S. Government Printing Office, Washington, DC

20402. 15. Price

[X

| Order From National Technical Information Service (NTIS), Springfield, VA 22161

uscoMM-DC ts-toat