Upload
megan-collins
View
221
Download
0
Tags:
Embed Size (px)
Citation preview
ULTRA FIRE RESISTANTTHERMOSET POLYMERS
Richard E. Lyon
Fire Research Program
Fire Safety Section AAR-440FEDERAL AVIATION ADMINISTRATION
W.J. Hughes Technical Center
Atlantic City International Airport, NJ 08405
ULTRA FIRE RESISTANT THERMOSET POLYMERS
OUTLINE OF TALK
• FAA Fire Resistant Materials Program
• Background of Bisphenol-C Polymers
• New Bisphenol-C Polymers
• Fire & Flammability Results
• Conclusions
Eliminate burning cabin materials as a cause of
death in aircraft accidentsby 2010.
FAA PROGRAM OBJECTIVE:
ThermosetResins
• 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
APPLICATIONSSupportingResearch
• New synthetic chemistries• Predict flammability from polymer chemical structure• Lab-scale method for measuring polymer fire hazard
PRODUCTS
PROGRAM DELIVERABLES
A VERSATILE BUILDING BLOCK IS NEEDED
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
Blends
OOClClHH(BPC = R) phthaloyl chlorides C l C l O– H2OPolyaryletherOCNOCNCyanate Ester R OOOO R R R n
Thermoplastics Thermosets
BACKGROUND: Bisphenol-C Polymers
1874: Chloral-phenol condensation reaction product (I)first reported.
1874: Dehydrochlorination to 1,1-dichloro, 2,2-bis(4-hydroxyphenyl) ethylene (bisphenol-C, BPC) first reported.
2HO+PhenolChloralCClClClHCO– H2OHOOHCCClClClHIH+
— HClBisphenol C (BPC)ClClCCHOOHHOOHCCClClClHI
1964: Polycarbonate from BPC first reported.
1965: “Self-Extinguishing Epoxies” from BPC first reported in Poland.
— HClBisphenol-C (BPC)ClClCCHOOHClClOC+PhosgeneCClClCOOOCBisphenol-C Polycarbonate
CH2CH–CH2–ClO2Epichlorhydrin—2 HCl+CH2—CH–CH2–OOO–CH2–CH—CH2ODiglycidylether of Bisphenol C (DGEBC)IIIClClCCBisphenol C (BPC)ClClCCHOOH
BACKGROUND: Bisphenol-C Polymers
GE begins research to obtain non-burning (XB) plastics. Investigates bisphenol-C, etherimide, and acetylenic polymers.
1970’s:
BACKGROUND: Bisphenol-C Polymers
• Acetylenic groups increase char yield in flame.
• Too many acetylenes increase flammability (decrease LOI)
C.B. Quinn, 1967—R—(-C≡ —C C≡ -)—C Char YieldOxygenIndex
% Diacetylene020406080100— —(-R C≡ -)—C% Acetylene020406080100CharYieldOxygenIndex
1970’s:
BACKGROUND: Bisphenol-C Polymers
GE develops and patents industrial process chemistry to make BPC-polycarbonate (XB-1) and polyetherimide (XB-2).
OOnCH3OONNCH3OO
OnCOClClO
GE downselects to XB-2 (ULTEM™) because of fire (UL) and high temperature (TEM) capability.
XB-2
XB-1
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.
BACKGROUND: Bisphenol-C Polymers
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
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 NonflamingCombustion
TEST METHOD REPRODUCES FLAMING COMBUSTION
Flaming CombustionPyrolysis-Combustion
Flow CalorimetrySampleExhaustN2DAQO2Polymer SolidFlameFlow-meter
O2AnalyzerPyrolyzerCombustorGas ScrubbersPyrolysis
Zone
slope = 1 kg-K/m2-s
HEAT RELEASE CAPACITY PREDICTS FIRE RESPONSE
(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 Chemicals/VanticoPerformance 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 patent filed by Ciba/Vanitco
BPC cyanate ester scaled-up and prepregged for bench scalefire calorimetry testing
1999-present:
University (UMASS, Rice) research continues onBPC copolymers and blends.
2000: “Thermal Decomposition Mechanism of…”, M. Ramirez, DOT/FAA/AR-00/42, and A. Factor, GE Plastics
CCl2CRΔCCl CRCl•• electron transferCCl CRCl–+CCl CRCl+–phenylmigrationC CRClCl– 2 (HCl↑)char– (R ↑) – Δ ( )exothermicC CR••
BACKGROUND: Thermal Degradation Mechanism Identified
350-450°C– 80 kJ/mole
2001: FAA Scales up BPC polycarbonate chemistry with Dow Chemical, Freeport TX
2002: U.S. Navy tests and approves BPC cyanate ester composites for use in submarines.
2003: VANTICO obtains composition of matter patent for BPC cyanate ester.
2004: NAVY awards SBIR programs to develop BPC thermoset process chemistry for large shipboard structures
BACKGROUND: Technology Transfer
BPC THERMOSET POLYMERS
Epoxy
Cyanate Ester
Epoxy-Cyanate Ester Blends
EPOXY
EPOXIES: Synthesis as per DGEBA
2— HClHO+PhenolChloralCClClClHCO– H2OCH2CH–CH2–ClO2EpichlorhydrinBisphenol C (BPC)—2 HClII+HOOHCCClClClHIClClCCHOOHCH2—CH–CH2–OOO–CH2–CH—CH2ODiglycidylether of Bisphenol C (DGEBC)IIIClClCCH+
EPOXY FORMULATIONS: Hardeners Examined
NH2H2NH2NNHNNH2H
NNHH3CCH2CH3
EMI-24(2 phr)
TETA(14 phr)
MDA(58 phr)
BPC(78 phr
DGEBC)
Cyanate esterof BPC
(53 phr DBEBC)
OHCCH3CH3HO
BPA(66 phr DGEBA)
–O–CH2–CH–CH2–O—CCClClOHa) DGEBC-BPC
CCClCl–O–CH2–CHOCH2b) DGEBC-EMI
“R” group for epoxy has relatively high
fuel value.
Dichloroethylidene (DCE) grouphas zero fuel value, but…
FIRE RESISTANCE OF BPC EPOXY LIMITEDBY HIGH FUEL VALUE OF GLYCIDYL ETHER
“R” Heat of combustion,hc = 7 kJ/g-polymer (theoretical)
= 11 kJ/g-polymer (measured)
EPOXY HEAT RELEASE CAPACITIES
DGEBCDGEBA
UL 94 V-0(typically)
EPOXY FIRE CALORIMETRY: Peak HRR
DGEBCDGEBAGlass fabric lamina
FAR 25.853 (a-1)
FAA Maximum
EPOXY FIRE CALORIMETRY: Total Heat Release
DGEBCDGEBA
FAA Maximum
Glass fabric laminaFAR 25.853 (a-1)
(2-min, flaming)
GLASS TRANSITION TEMPERATURE
STIFFNESS STRENGTH
MECHANICALS: BPA ( ) vs. BPC ( ) Epoxy
HEAT OFPOLYMERIZATION
CYANATE ESTERS
CYANATE ESTER: Polymerization Reaction
OCNCClClNCO
200°C
BPC triazine thermoset polymer
BPC cyanate ester monomer
EFFECT OF BISPHENOL ON HEAT RELEASE RATEOF CYANATE ESTERS
ASTM 1354, cone calorimeter at 50 kW/m2 heat flux, neat resin, 1/4-inch thick
BPC CYANATE ESTER: FAA Heat Release Rate Test
glass fabric lamina
glass fabric lamina
1/8-in NOMEX honeycomb
STRUCTURAL COMPOSITES FOR NAVY SUBMARINES
Fire Test/Characteristic Requirement(MIL-STD-2031)
BPC-CETime to ignition (s) at irradiance:
100 kW/m2
75 kW/m2
50 kW/m2
25 kW/m2
Peak/Average Heat Release Rate (kW/m2) at irradiance:
Smoke Obscuration, Dmax/Ds (avg):100 kW/m2
75 kW/m2
50 kW/m2
25 kW/m2
> 300
> 150
> 90> 60
< 50/50
< 65/50
< 100/100
< 150/120
Composite Resin Phthalo-
nitrile Silicone
Combustion Gas Toxicity (CO/CO2/HCN/HCl):
Mechanical Properties
pass
passpass
pass
pass
passpass
pass
pass
passgood
pass
passpass
pass
pass
passpass
pass
N/A
N/Agood
pass
passpass
pass
pass
passpass
pass
pass
passpoor
< 200/100
Only 3 resins pass fire performance requirements as glass composites:
J. Koo, et. al., SAMPE 2001
Cure Temperature < 200°C > 375°C N/A
CYANATE ESTER-EPOXYBLENDS
0
100
200
300
400
500
600
0
5
10
15
20
25
30
35
40
0 0.2 0.4 0.6 0.8 1
Hea
t R
elea
se C
apac
ity
of
Ble
nd
, J/
g-K
(Baselin
e Co
rrected)
OS
U P
eak HR
R, kW
/m2
Mole Fraction BPC-Epoxy in Blend
FIRE PERFORMANCE OF BPC(CE-EP) BLENDS
CONCLUSIONS: Comparing Properties
Fire Hazard Potential (c):
Fire Hazard (HRR):
Glass Transition Temperature, K:
Modulus:
Yield Strength:
Yield Strain:
BPC / BPA
– 90 %
– 60 %
+ 3 %
+ 10 %
+ 10 %
+ 10 %
Average Change (5-7 polymers)
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