Synthesis of New Low-Temperature Petroleum-Resistant Elastomers

摘要

The copolymer, (NP(OCH2CF3)2 - NP(OCH2C3F7)2)n, is an elastomer with a glass transition temperature of -77C that has an initial decomposition point of 300C in air on a thermobalance at a heating rate of 2 1/2 deg C minute. A high molecular weight sample had a tensile strength of 680 psi and an elongation of 800 per cent. The elastomer is very inert chemically and is soluble only in selected fluorocarbon solvents. When placed in a direct flame, the material softened and vaporized but would not burn. The copolymer has been successfully scaled up to the one-half pound scale. Preliminary experiments have demonstrated the feasibility of cures with certain peroxides or amines at 300F. The preparation and characterization of a number of analogous materials has been initiated. These include the (NP(OCH2C3F7)2)n homopolymer, which may be of utility as a base for solvent and chemical resistant coatings; the (NP(OCH2C3F7)2) - (NP(OCH2C7F15)2)n copolymer, which appears to be more solvent and chemically resistant than the copolymer of primary interest; and the (NP(OCH2C2F4H)2) - NP(OCH2C6F12H2)n copolymer, which appears to have a desirable combination of properties and utilizes relatively inexpensive starting materials. (Author)