Retraction Test for Serviceability of Elastomers at Low Temperatures

Abstract

Elastomer vulcanizates progressively stiffen as the temperature is lowered. Additional stiffening, due to crystallization, may occur as exposure to low ternperatures is prolonged. The available methods of testing the low temperature flexibility of rubber and rubberlike materials do not reveal the losses in flexibility caused by crystallization except by using prolonged storage at low temperatures. A retraction test employing large deformations, which greatly increases the rate of crystallization, has been developed. This test rapidly gives a temperature index correlating with the stiffness of elastomer vulcani-* HEN the temperature is lowered, the flexibility of a polymer