Calculation of impact transition temperature of low density polyethylene from shift factor via a free volume approach

Abstract

A relationship between the impact transition temperature Ti and the stress concentration factor Ks is derived. The relationship involves the temperature shift factor aT; in turn, a m depends on the free volume. In earlier work in this problem Zewi and Corneliussen [6] utilized the W-L-F equation. Here a more direct relationship between a T and the free volume is applied. Satisfactory values of Ks corresponding to given T i are obtained for a wide temperature range; the range also includes temperatures below the glass transition point Tg. The opinion that a free volume exists between 0 K and Tg is upheld.