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Cure Systems for High Performance Elastomers
ABSTRACT:
Increasing constraints in space and engine compartment temperature have placed increased demands in thermal and chemical resistance of many under the hood polymers. Increased influence from environmental and “maintenance-free requirements” are also changing the service conditions for rubber parts under the hood in modern engine compartments.
Continued trends are guiding the development of materials for smaller, lighter, higher horsepower engines, including resistance to aggressive fuels and oils, increasing need for dynamic endurance combining environmentally harmless and non-hazardous properties of materials. Polymer manufacturers continue to develop new materials with the assistance of additive suppliers to meet the ever increasing technical requirements of the automotive industry.
Prohibitive use of various heavy metals such as cadmium, hexavalent chromium and lead have changed the use of polymers and caused regional differences of curing systems. High performance elastomers depend strongly on the performance of the associated cure system. Besides peroxide cure systems, a variety of alternative cure systems are in use. This paper will give an overview of existing and newly available cross-linking systems for several affected polymers. Influences on physical properties and processability are shown for comparison purposes.