Low temperature dynamic seals with good fire resistance and chemical stability are required in space structures such as rocket boosters. Conventional methods of crosslinking and curing perfluoroether fluids have proved very difficult and costly to apply to the production of perfluoroether elastomers. Direct fluorination methods are being applied to novel, crosslinked polyethers which are being converted to the corresponding perfluoroether elastomers with f2 gas. Success depends on finding new co-agents which provide homogeneous carbon-carbon crosslinks in the substrate hydrocarbon ether before fluorination, and will survive f2 treatment to yield fluorinated structures. Reaction conditions are being formulated where potential co-agents such as divinyl ethers can graft to and crosslink polyethers by free-radical reactions or radiation. The suitability is being explored of fillers such as various carbon-blacks to enhance the physical properties of the cured polymers. The molecular weight and composition of the polyether starting materials are being optimized to achieve the desired parameters. Fluorination conditions are being identified that will yield perfluorinated elastomeric products with good physical properties. Orings are being prepared from both types of polymer backbones and their properties characterized so that a cost-effective decision can be made on their usefulness.
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