# Presentation: 240484

## ULTRA FIRE RESISTANTTHERMOSET 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 

***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**

## FAA PROGRAM OBJECTIVE:

**FAA PROGRAM OBJECTIVE:**

## PROGRAM DELIVERABLES

**PROGRAM DELIVERABLES**

## A VERSATILE BUILDING BLOCK IS NEEDED

- 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.

## BACKGROUND: Bisphenol-C Polymers

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

**BACKGROUND: Bisphenol-C Polymers**

## BACKGROUND: Bisphenol-C 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*

## BACKGROUND: Bisphenol-C Polymers

**BACKGROUND: Bisphenol-C Polymers**

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

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

- XB-2

- XB-1

## BACKGROUND: Bisphenol-C Polymers

- 	• 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

**BACKGROUND: Flaming Heat Release Rate Measured**

**1997:**  	FAA measures flaming heat release rate of
- 	BPC polycarbonate in OSU fire calorimeter.

**1998: ****	****FAA develops milligram-scale heat release rate test**
**	****to accelerate search for new polymers **

***Forced ***
***Nonflaming***
***Combustion***

## TEST METHOD REPRODUCES FLAMING COMBUSTION

## slope = 1 kg-K/m2-s

***slope = 1 kg-K/m******2******-s***

**HEAT RELEASE CAPACITY PREDICTS FIRE RESPONSE **

***(as per 1-D burning model) ***

- Provides new capability for rapid screening of research polymers
- for fire resistance.

## BACKGROUND: Flammability Screening Yields Results

**1998: ****	****FAA collaborates with Ciba Specialty Chemicals/Vantico**
**	****Performance Polymers Division, Brewster, NY to develop ultra**
**	****fire resistant cyanate ester thermoset resins for aircraft interiors**
**	**
**	****BPC cyanate ester identified as having lowest  heat release**
**	****capacity of any thermoset tested to date**
**	****BPC cyanate ester patent filed by Ciba/Vanitco**
**	****BPC cyanate ester scaled-up and prepregged for bench scale**
**	****fire calorimetry testing **

**1999-present:**
- 	**University (UMASS, Rice) research continues on**
**	****BPC copolymers and blends.**

## BACKGROUND: Thermal Degradation Mechanism Identified

**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**

## Epoxy

**Epoxy**
**	****Cyanate Ester**
**	****	****Epoxy-Cyanate Ester Blends**

## EPOXY

## EPOXIES: Synthesis as per DGEBA

## EPOXY FORMULATIONS: Hardeners Examined

**EMI-24**
- (2 phr)

**TETA**
- (14 phr)

**MDA**
- (58 phr)

**BPC**
- (78 phr
- DGEBC)

**Cyanate ester**
**of BPC**
- (53 phr DBEBC)

**BPA**
- (66 phr DGEBA)

## FIRE RESISTANCE OF BPC EPOXY LIMITED

***“******R” group for epoxy has relatively high fuel value.***

***Dichloroethylidene (DCE) group***
***has ***_***zero***_*** fuel value, but...***

**FIRE RESISTANCE OF BPC EPOXY LIMITED**
**BY HIGH FUEL VALUE OF GLYCIDYL ETHER**

_***“***__***R” Heat of combustion***_***,***
***h******c****** =   7 kJ/g-polymer (theoretical)***

*= 11 kJ/g-polymer (measured)*

## EPOXY HEAT RELEASE CAPACITIES

**DGEBC**

**DGEBA**

*UL 94 V-0*
*(typically)*

## EPOXY FIRE CALORIMETRY: Peak HRR

**DGEBC**

**DGEBA**

**Glass fabric lamina**
**FAR 25.853 (a-1)**

**FAA Maximum**

## EPOXY FIRE CALORIMETRY: Total Heat Release

**DGEBC**

**DGEBA**

**FAA Maximum**

**Glass fabric lamina**
**FAR 25.853 (a-1)**

**(2-min, flaming)**

## MECHANICALS: BPA (	) vs. BPC (	) Epoxy

**GLASS TRANSITION**
** ****TEMPERATURE**

**STIFFNESS **

**STRENGTH **

**MECHANICALS: BPA (****	****) vs. BPC (****	****) Epoxy**

**HEAT OF**
**POLYMERIZATION **

## CYANATE ESTERS

## CYANATE ESTER: Polymerization Reaction

- 200°C

***BPC triazine thermoset polymer***

***BPC cyanate ester  monomer***

## EFFECT OF BISPHENOL ON HEAT RELEASE RATE

**EFFECT OF BISPHENOL ON HEAT RELEASE RATE**
**OF 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

**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-CE

**Time to ignition (s) at irradiance:**

- 100 kW/m2

- 75 kW/m2

- 50 kW/m2

- 25 kW/m2

**Peak/Average Heat Release Rate  (kW/m****2****) at irradiance:**

**Smoke Obscuration, D****max****/D****s**** (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/CO****2****/HCN/HCl):**

**Mechanical Properties**

- pass

- pass

- pass

- pass

- pass

- pass

- pass

- pass

- pass

- pass

- good

- pass

- pass

- pass

- pass

- pass

- pass

- pass

- pass

- N/A

- N/A

- good

- pass

- pass

- pass

- pass

- pass

- pass

- pass

- pass

- pass

- pass

- poor

- < 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-EPOXY

**BLENDS**

## FIRE PERFORMANCE OF BPC(CE-EP) BLENDS

- 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

**Heat Release Capacity of Blend, J/g-K**

**(Baseline Corrected) **

**OSU Peak HRR, kW/m****2**

**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

**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 *