fire resistant polymers based on bisphenol-c · pdf filefire resistant polymers based on...

FIRE RESISTANT POLYMERS BASED ON BISPHENOL-C

Richard E. Lyon

Fire Research ProgramFire Safety Section AAR-422

FEDERAL AVIATION ADMINISTRATIONW.J. Hughes Technical Center

Atlantic City International Airport, NJ 08405

OUTLINE OF TALK

FIRE RESISTANT BISPHENOL-C POLYMERS

• FAA Fire Resistant Materials Program

• Background of Bisphenol-C Polymers

• New Bisphenol-C Polymers

• Fire & Flammability Results

• Conclusions

FAA PROGRAM OBJECTIVE:

Eliminate burning cabinmaterials as a cause of

death in aircraft accidents by 2010.

A WIDE RANGE OF DELIVERABLES

Thermoset Resins

• Interior decorative panels • Secondary composites • Adhesives

Thermoplastics • Decorative facings • Telecommunications equipment • Molded seat parts • Passenger service units • Electrical wiring • Transparencies/glazing • Thermoacoustic insulation films

Textile Fibers • Upholstery • Carpets • Murals • Tapestries • Thermoacoustic insulation blankets

Elastomers (rubber)

• Seat cushions • Pillows • Sealants/gaskets

APPLICATIONS

Supporting Research

• New synthetic chemistries • Predict flammability from polymer chemical structure • Lab-scale method for measuring polymer fire hazard

PRODUCTS

A VERSATILE BUILDING BLOCK IS NEEDEDThermoplastics Thermosets

C l C ≡N

p h o s g e n e

O

O O n

Polycarbonate

O

O O

O

n Polyester

Epoxy e p i c h l o r o h y d r i n

Epoxy-Cyanate Ester

BlendsO O

ClCl

H H(BPC = R)

phthaloyl chlorides

C l C l

O

– H2O

Polyarylether

O C NOCN

Cyanate Ester R

OO

OO

R R

R

n

GAPS IN MATERIALS FIRE SAFETY TECHNOLOGY

A. Affordable routes to ultra fire resistant polymers

B. Ultra fire resistant polymers with:• low/moderate processing temperature

• good strength & toughness• colorability and colorfastness

C. Relationship between material properties and fire performance.

D. Relationship between chemical composition and fire performance.

E. Scaling Relationships: micro-, bench-, quarter-, full-scale

F. Fundamental understanding of fire resistance mechanisms

(Attributes of Bisphenol-C Based Polymers)

BACKGROUND: Bisphenol-C Polymers

1874: Chloral-phenol condensation reaction product (I)first reported.

2 HO +

Phenol Chloral

CCl

Cl

ClHC

O

– H2OHO OH

CC

Cl ClCl

HI

H+

1874: Dehydrochlorination to 1,1-dichloro, 2,2-bis(4-hydroxyphenyl) ethylene (bisphenol-C, BPC) first reported.

— HCl

Bisphenol C (BPC)

Cl ClC

CHO OHHO OHCC

Cl ClCl

HI


1964: Polycarbonate from BPC first reported.

— HCl

Bisphenol-C (BPC)

Cl ClC

CHO OHCl Cl

OC+

Phosgene

CCl Cl

CO OOC

Bisphenol-C Polycarbonate

1965: “Self-Extinguishing Epoxies” from BPC first reported in Poland.

CH2 CH–CH2–ClO

2Epichlorhydrin

— 2 HCl+ CH2—CH–CH2–O

OO–CH2–CH—CH2

O

Diglycidylether of Bisphenol C (DGEBC) III

Cl ClC

CBisphenol C (BPC)

Cl ClC

CHO OH


1970’s: GE begins research to obtain non-burning (XB) plastics. Investigates bisphenol-C, etherimide, and acetylenicpolymers.

C.B. Quinn, 1967—R—(-C≡C—C≡C-)—

Char Yield

Oxygen Index

% Diacetylene

0 20 40 60 80 100

—R—(-C≡C-)—

% Acetylene

0 20 40 60 80 100

Char Yield

Oxygen Index

• Acetylenic groups increase char yield in flame.

• Too many acetylenes increase flammability (decrease LOI)


1970’s:GE develops and patents industrial process chemistry to make BPC-polycarbonate (XB-1) and polyetherimide (XB-2).

O

n

CO

Cl Cl

O XB-1

O

O

n

CH3

O

O

N N

CH3

O O XB-2

GE downselects to XB-2 (ULTEM™) because of fire (UL) and high temperature (TEM) capability.


1980’s – 1990’s: Research in chloral condensation polymers continues in Poland and Russia but not in U.S.A.

• Fire testing limited to flame tests (flammability).• High LOI (50-60) and “self-extinguishing” behavior attributed to

chlorine content.• No commercial activity.

1994: Comprehensive review:

Condensation Polymers Based on Chloral And Its Derivatives,

A.L. Rusanov, Progress In Polymer Science, Vol. 19, pp. 589-662 (1994)

BACKGROUND: Flaming Heat Release Rate Measured

Char Yield (%)

25

54

L.O.I. [%O2]

26

56

UL 94

V-0

V-2

Polymer

CCl2

C O C

O

n

OO C

OCH3

C

CH3 n

O

BPA

BPC

FAR25.853(a-1) Peak/Total*

(kW/m2) (kW-min/m2)

*1/16-inch (0.063 in) sample

thickness

153 / 58

55 / 33

1997: FAA measures flaming heat release rate ofBPC polycarbonate in OSU fire calorimeter.

BACKGROUND: New Flammability Screening Test

1998: FAA develops milligram-scale heat release rate testto accelerate search for new polymers

Forced Non-flamingCombustion

TEST METHOD REPRODUCES FLAMING COMBUSTION

Flaming Combustion

Pyrolysis-Combustion Flow Calorimetry

Sample

Exhaust

N2

DAQO2

Polymer Solid

Flame

Flow-meter

O2 Analyzer

Pyrolyzer

Combustor

Gas Scrubbers

Pyrolysis Zone

MOLECULAR FIRE PARAMETER IDENTIFIED

Dividing the peak kinetic heat release rate by β gives a material property, the Heat Release Capacity

(J/g-K)ηc h c 0 ( 1 – µ ) E a

eR T p 2 ≡

max •

β = Qc

h c 0 = Heat of Combustion of Fuel Gases

E a = Global Activation Energy for Pyrolysis µ = Char Fraction

e = The natural number 2.7183…

T p = Temperature at Peak Mass Loss Rate

= Gas Constant R

HEAT RELEASE CAPACITY PREDICTS FIRE RESPONSE

0

200

400

600

800

1000

1200

1400

Ave

rage

Fla

min

g H

RR

(kW

/m2 )

Heat Release Capacity (J/g-K)

250 15000 500 750 1000 1250

POM

PEPS

ABS

PBTPMMA

PESF

PEI

Nylon 66

Epoxy

PAI

PC

PEEK

PTPET

PPqext = 50 kW/m• 2

slope = 1 kg-K/m2-s(as per 1-D burning model)

Provides new capability for rapid screening of research polymersfor fire resistance.

BACKGROUND: Flammability Screening Yields Results

1998: FAA collaborates with Ciba Specialty ChemicalsPerformance Polymers Division, Brewster, NY to develop ultrafire resistant cyanate ester thermoset resins for aircraft interiors

BPC cyanate ester identified as having lowest heat releasecapacity of any thermoset tested to date

BPC cyanate ester patents filed by Ciba

BPC cyanate ester scaled-up and prepregged for bench scalefire calorimetry testing

1999-present:

University (UMASS, Rice) research continues onBPC copolymers and blends.

BACKGROUND: Thermal Degradation Mechanism Identified2000: “Thermal Decomposition Mechanism of…”, M. Ramirez,

DOT/FAA/AR-00/42, and A. Factor, GE Plastics

CCl2

CR∆

CCl

CR

Cl• •

electron transfer

CCl

CR

Cl–+CCl

C

R

Cl +–

phenyl migration

C CRCl

Cl – 2 HCl (↑)

char– R (↑)

– ∆ (exothermic)

C CR••

350-450°C– 80 kJ/mole

BPC THERMOPLASTICS

Polycarbonate

Polyetherketone

Polyarylates

POLYCARBONATE: BPA vs BPC

LEXAN™ Chloral

Polycarbonate

Tg (°C) 168152Flex Modulus (ksi) 376336Flex Strength (psi) 16,300 16,200

NBS Smoke (Dm) 165 75Oxygen Index (%) 5626

Tensile Yield Strain (%) 10 11


390 29

Morphology Amorphous Amorphous

OO C

OCH3

C

CH3 n

CCl2

C OO C

O

n

FAR 25.853(a-1) Heat Release Peak/Total* (kW/m2) / (kW-min/m2)

*0.063 in153 / 58 55 / 33

POLYETHERKETONE: Carboxyl vs. DCE

O C

O

n

ULTRAPEK™ ChloralPolarylether

CCl2

CO

n

Tg (°C) 161 166

Flex Modulus (ksi) 426530Flex Strength (psi) 18,900 18,000

NBS Smoke (Dm) 17N/AOxygen Index (%) 5234

Tensile Yield Strain (%) 7 10

124 20

Morphology Semicrystalline Amorphous

Tm (°C) 381 N/A


POLYARYLATES: BPA vs. BPC

HDT (°C) 160-174Flex Modulus (ksi) 391325Flex Strength (psi) 11,000 11,700

NBS Smoke (Dm) N/A109Oxygen Index (%) 4736

Tensile Failure Strain (%) 50 50

460 18

Morphology Amorphous


n

RC

O

C

O

OO

CH3

CCH3

R = R =

Amorphous160

C

C

Cl Cl

POLYARYLATE: BPA-BPC Copolymers & Blends

Flammability does notfollow simplerules of mixtures.

0

100

200

300

400

500

0 20 40 60 80 100

Hea

t Rel

ease

Cap

acity

, J/g

-K

Mole Percent BPC

BlendsCopolymers

020406080100

Mole Percent BPA

UpperBound

LowerBound

Rules of Mixtures

—C—O—

O

O—C

O

50/50 iso/para

—R—

BPA or BPC

C

CCl Cl

R =(BPC) (BPA)

CCH3H3C

J.R. Stewart, 2000

BPC THERMOSET POLYMERS

Epoxy

Cyanate Ester

Epoxy-Cyanate Ester Blends

EPOXIES: Synthesis as per DGEBA

2

— HCl

HO +

Phenol Chloral

CCl

Cl

ClHC

O

– H2O

CH2 CH–CH2–ClO

2

Epichlorhydrin Bisphenol C (BPC)— 2 HCl

II

+

HO OHCC

Cl ClCl

HI

Cl ClC

CHO OH

CH2—CH–CH2–OO

O–CH2–CH—CH2O

Diglycidylether of Bisphenol C (DGEBC) III

Cl ClC

C

H+

EPOXY FORMULATIONS: Hardeners Examined

N

N

H

H3C

CH2CH3

EMI-24(2 phr)

NH2

H2N MDA(58 phr)

H2NN

H

NNH2

HTETA(14 phr)

OCN

Cl

Cl

NCO Cyanate esterof BPC

(53 phr DBEBC)

OH

Cl

Cl

HOBPC

(78 phrDGEBC)

OHC

CH3

CH3

HO

BPA(66 phr DGEBA)

FIRE RESISTANCE OF BPC EPOXY LIMITEDBY HIGH FUEL VALUE OF GLYCIDYL ETHER

–O–CH2–CH–CH2–O—CC

Cl ClOH

a) DGEBC-BPC

CC

Cl Cl

–O–CH2–CHO

CH2

b) DGEBC-EMI

Dichloroethylidene (DCE) grouphas zero fuel value, but…

“R” Heat of combustion,hc = 7 kJ/g-polymer (theoretical)

“R” group for epoxy has relatively high

fuel value.

= 11 kJ/g-polymer (measured)

EPOXY HEAT RELEASE CAPACITIES

DGEBA DGEBC

EMI-24 TETA MDA BPA BPC CEBPC

Hardener

0

200

400

600

800

1000

Hea

t Rel

ease

Cap

acity

, J/g

-K

UL 94 V-0(typically)

EPOXY FIRE CALORIMETRY: Peak HRR

DGEBCDGEBA

0

50

100

150

Peak

Rat

e of

Hea

t Rel

ease

, kW

/m2


Hardener

Glass fabric laminaFAR 25.853 (a-1)

FAA Maximum

EPOXY FIRE CALORIMETRY: Total Heat ReleaseGlass fabric lamina

FAR 25.853 (a-1)DGEBA DGEBC

0

10

20

30

40

50

60

70

Tota

l Hea

t Rel

ease

, kW

-min

/m2


Hardener

FAA Maximum

(2-min, flaming)

MECHANICALS: BPA ( ) vs. BPC ( ) Epoxy

0

20

40

60

80

100

120

140

Yiel

d St

ress

, MPa

EMI-24 TETA MDA

Hardener

STRENGTH

0

0.5

1.0

1.5

2.0

2.5

3.0

Youn

g’s

Mod

ulus

, GPa

EMI-24 TETA MDA

Hardener

STIFFNESS

0

20

40

60

80

100

120

140

²Hpo

lym

, kJ/

mol

e


Hardener

HEAT OFPOLYMERIZATION

Gla

ss T

rans

ition

Tem

pera

ture

, °C


Hardener

0

50

100

150

200

250

No

data

GLASS TRANSITIONTEMPERATURE

FLAMMABILITY: BPA ( ) vs. BPC ( ) Epoxy

Oxygen Index UL 94


Hardener

0

5

10

15

20

25

30

35

40

Lim

iting

Oxy

gen

Inde

x, %

O2

(v/v

)

No

data

No

data

No

data V-0

V-1

V-2

HB

UL

94 R

anki

ngEMI-24 TETA MDA BPA BPC CEBPC

Hardener

5V No

data

No

data

COMBUSTABILITY: BPA ( ) vs. BPC ( ) Epoxy

DecompositionTemperature Heat of Combustion

0

5

10

15

20

25

30

Hea

t of C

ombu

stio

n, k

J/g-

poly

mer


Hardener

0

100

200

300

400

500

Peak

Mas

s Lo

ss R

ate

Tem

pera

ture

, °C


Hardener

< DGEBA >

< DGEBC >

0

10

20

30

Cha

r Yie

ld, %

(w/w

)


Hardener

Char Yield50

40

CYANATE ESTER: Polymerization Reaction

OCNC

Cl Cl

NCO

N

NN

CCl Cl

CCl

Cl

CClCl

200°C

BPC triazine thermoset polymer

BPC cyanate ester monomer

EFFECT OF BISPHENOL ON HEAT RELEASE RATEOF CYANATE ESTERSASTM 1354, cone calorimeter at 50 kW/m2 heat flux, neat resin, 1/4-inch thick

CNCO

CH 3

CH 3

OCN

CNCO

CH 3

H

OCN

NCO CH 2 OCN

CH 3

CH 3H3C

H3C

CCCH 3

CH 3

CH3

CH3

NCO OCN

NCO OCN

CClCl

C

0 200 400 600 800 1000 1200

Hea

t Rel

ease

Rat

e, k

W/m

2

Time, seconds

200 kW/m2

BPC CYANATE ESTER: FAA Heat Release Rate Test

-10

0

10

20

30

40

50

60

Hea

t Rel

ease

Rat

e, k

W/m

2

0 50 100 150 200 250 300 350Time, sec

2current AC phenolic panel

BPC cyanate ester panel

FAR 25.853(a-1)

glass fabric lamina1/8-in NOMEX honeycomb

glass fabric lamina

STRUCTURAL COMPOSITES FOR NAVY SUBMARINESOnly 3 resins pass fire performance requirements as glass composites:

Fire Test/Characteristic Requirement(MIL-STD-2031)

Composite Resin Phthalo-

nitrile SiliconeBPC-CETime to ignition (s) at irradiance:

passpass25 kW/m2 > 300 passpasspass> 15050 kW/m2 passpasspasspass> 9075 kW/m2

passpass> 60 pass100 kW/m2

Peak/Average Heat Release Rate (kW/m2) at irradiance:passpass< 50/50 pass25 kW/m2

passpass< 65/50 pass50 kW/m2

passpasspass< 100/10075 kW/m2

passpassSmoke Obscuration, Dmax/Ds (avg):

100 kW/m2 < 150/120 pass< 200/100 passN/Apass

Combustion Gas Toxicity (CO/CO2/HCN/HCl): passN/ApasspoorgoodgoodMechanical Properties

Cure Temperature < 200°C > 375°C N/A

J. Koo, et. al., SAMPE 2001

CYANATE ESTER-EPOXY REACTIVE BLENDSBPC Cyanate Ester (Ciba RD 98-228)

C16H8O2Cl2

MW: 331.16 g/molEW: 165.58 g/eqMP: 75 ± 2 °CCl: 21.41 wt%

CNCO

CCl Cl

OCN

BPC Epoxy (Pacific Epoxy XPR-1015)

C OO CH2CH2 CH CH2CHO

H2CO C

Cl ClMW: 393.27 g/molEW: 209.39 g/eqMP: 91 ± 4 °CCl: 16.93 wt%

C20H18O4Cl2

BPC Blends Cyanate:Epoxy %Cl1:08:26:44:62:80:1

21.420.519.618.717.816.9

Blend ratios prepared from the reported equivalent weights

CYANATE ESTER-EPOXY REACTION

Cyclotrimerization reaction of the cyanate ester (A) and the subsequent reaction with the glycidylether (B) to form the oxazoline

Cyanate Ester OxazolineTriazine

3 33(A) (B)

N

O CH2O

OR'

RCHH2C

O

CH2

OR'

²+

NN

NO

O

O

RR

R

OC N

R²

Glycidylether

Glycidylether OxazolidoneIsocyanurate

N

N

N

O

OO

R

R

R CHH2CO

CH2

OR'

O N

O

R

OR'

+ 3 3²

(D)(C)

Rearrangement of the triazine (C) to form isocyanurate and the subsequent reaction with the glycidylether (D) to form the oxazolidone

FTIR MONITORING OF CE-EP CURE CHEMISTRY

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

100 150 200 250 300

Nor

mal

ized

Pea

k H

eigh

t

Temperature (°C)

Cyanate Ester Epoxy Triazine Oxazoline

FIRE PERFORMANCE OF BPC CYANATE ESTER-EPOXY BLENDS

0

100

200

300

400

500

0

5

10

15

20

25

30

35

0 0.2 0.4 0.6 0.8 1

Hea

t Rel

ease

Cap

acity

of B

lend

, J/g

-K(B

aseline Corrected)

OSU

Peak HR

R, kW

/m2

Mole Fraction BPC-Epoxy in Blend

40600

CONCLUSIONS: Comparing Properties

Average Change (5-7 polymers)

BPC / BPA

– 90 %Fire Hazard Potential (ηc):

Fire Hazard (HRR): – 60 %

Glass Transition Temperature, K: + 3 %

Modulus: + 10 %

+ 10 % Yield Strength:

Yield Strain: + 10 %

ACKNOWLEDGEMENTS

Jennifer Stewart, Huiquing Zhang, UMASS

Lauren Castelli, Mike Ramirez, FAA

Arnie Factor, Mike MacLaury, GE Plastics

Borsheng Lin, Mike Amone, Ciba Specialty Chemicals

Richard Walters, Galaxy Scientific

Gary Green, Pacific Epoxy

fire resistant polymers based on bisphenol-c · pdf filefire resistant polymers based on...

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