Automotive fuels high temperature resistance

High temperature resistance of ETEE and other fluoropolymers ia automotive fuels and their permeation resistance have been discussed (28,29). 

Appendix I High Temperature Resistance of Fluoropolymers in Automotive Fuels... 

Values in () indicate the specific effect of the fuel exposure Appendix I High Temperature Resistance of Fluoropolymers in Automotive Fuels... 

Society of Automotive Paper Series 910103, Parti. High Temperature Resistance of Fluoropolymer in Automotive Fuels. 

Medium-molecular-weight PMTFPS with vinyl or hydroxyl end blocks are used for adhesives and sealants. They are cured either at ambient temperature (RTV-room temperature vulcanization) or at elevated temperature. One-part moisture-activated RTV sealants have been available commercially for many years. Because of then-very high resistance to jet engine fuels, excellent flexibility at very low temperatures, and high thermal stability, they have been used in both military and civilian aerospace applications.78 Two-part, heat-cured fluorosilicone sealants have been used in military aircraft applications and for sealing automotive fuel systems.79 Special class of fluorosilicone sealants are channel sealants or groove injection sealants, sticky, puttylike compounds, which do not cure. They are used to seal fuel tanks of military aircraft and missiles.75... 

The use of aromatic compounds in automotive fuels, higher under-the-hood temperatures, combined with automotive regulations, presents a challenge for the rubber parts (e.g., hose, seals, diaphragms) used in vehicles. Traditional elastomers do not have high enough resistance to meet all these requirements, but fluorocarbon... 

PA/ABS high temperature warp resistance, chemical resistance, good processability, and superior appearance, automotive (body panels, under-the-hood connectors and components, fuel tanks, bearings, bushings, cams). 

Most butyl rubber is used in the tire industry. Isobutylene-based rubbers are used in underhood hose for the polymer s low permeability and temperature resistance, and high damping, resihent butyl rubbers are used for noise and vibration attenuation applications such as automotive mounts for the engine and vehicle. Chloro- and brominated butyl rubber formulations are used in automotive hose applications where contact with fuel or air conditioning fluids occurs. 

The fluorinated rubbers are exceptionally good for high-temperature service, but they are below silicones in this respect. They resist most of the lubricants, fuels, and hydraulic fluids encountered in aircraft a wide variety of chemicals, especially the corrosive variety and also most chlorinated solvents. They have good physical properties, somewhere near those of styrene butadiene rubber (SBR) at the higher hardness levels. FKM is valnable in automotive use for its extreme heat and oil resistance and is on a much higher level in this respect than the acrylic elastomers. It has weathering properties snperior to those of neoprene. However, fluoroelastomers are relatively expensive. 

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