Cold Compression Set of Elastomer Vulcanizates

Butadiene Polymers for Low Temperature Service

“…The rise of compression set with time of conditioning is attributed to crystallization (10). Crystallization of the rubber in a gasket is particularly undesirable since it causes partial or complete loss of sealing ability (9). Crystallization also hardens the rubber as evidenced by the indentation data in Table I.…”

“…rubbers containing more than 16% combined styrene (see Figure 1). It has been shown that excessive internal viscosity is just as detrimental to the sealing ability of gaskets as crystallization (9).…”

Elastomers

“…Methods used at the Rock Island Arsenal are described. The low temperature compression set test, as used at the Mare Island Naval Shipyard, has been described, and the correlation of low temperature set of gaskets with their actual sealing capacity demonstrated experimentally (107). Recovery stress under compression is a manifestation of the entropy of the rubber, and any change that reduces the entropy reduces the sealing capacity of a gasket.…”