The Effect of Temperature on the Rate of Creep Failure for 66 Nylon

Abstract

Measurements have been made of the lifetime under dead load behavior of high tenacity bright nylon yarn in dry nitrogen at eight temperatures in the range 30-125° C. The data obtained have been interpreted using a previously published absolute reaction rate theory of the creep failure of oriented crystalline polymeric fibers. The prediction of the theory that the logarithm of the lifetime should be a linear function of the sus tained dead load was found to be consistent with the experimental results at all tem peratures investigated. The data were used to calculate estimates at each temperature for the displacement volume δ and the free energy of activation ΔF ^‡ for the breakdown process. An examination of the temperature dependence of ΔF ^‡has yielded the con clusion that the negentropy of activation — Δ S ^‡ makes a negligible contribution to ΔF ^‡. The best estimate for the heat of activation for breakdown Δ H ^‡ was found to be ∼49 kcal.