Organic solvent treatment of isotactic polypropylene films, 2. Temperature dependence of proton spin‐lattice and spin‐spin relaxation times of the sample treated with tetrachloroethylene

Abstract

AbstractThe structural properties of isotactic polypropylene films treated with tetrachloroethylene at high temperatures were characterized by proton spin‐lattice T1 and spin‐spin T2 relaxation times, loss in weight, crystallinity, molecular weight, and melting temperature, and heat of fusion. Two kinds of samples, a quenched and an annealed sample, were employed. There are a considerable loss in weight and large increases in crystallinity and in molecular weight when treated the sample at high temperatures especially in the quenched one. These morphological changes result in a shift of T1 minimum to high temperatures and a decrease in T2a. The effects of the solvent on the annealed sample are qualitatively the same for the quenched one but are relatively mild.