ANISOTROPIC CREEP-BEHAVIOR OF ORIENTED POLYCARBONATE

The anisotropic character of the creep behaviour of polycarbonate, ori ented at a temperature 12-degrees-C above the glass transition to diff erent draw ratios, has been studied using the model of Boyd and Jansso n. This model is based on molecular assumptions and results in a secon d-order relation, epsilon = D1sigma + D2sigma2, where D1 is the linear and D2 the non-linear compliance component. The segmental orientation was determined by infra-red dichroism and the chain extension by shri nkage. It was found that both the linear and non-linear compliance com ponents decreased with increasing orientation, although the non-linear component is affected much more by the orientation. The same result w as found both in tension and contraction.