Kinetics of spherulite and crystallite growth in isotactic polystyrene

Abstract

The rates of spherulite and crystal growth in isotactic polystyrene have been studied as a function of temperature by microscopic, x‐ray, and density methods. The effects of molecular weight and degree of isotacticity upon the spherulite growth are shown. Degree of isotacticity is the predominant factor in growth rate. Maximum rate of spherulite growth was observed at 175°C., while the maximum rate of crystal growth was observed at 190°C. Some evidence exists that polystyrenes made with the use of heterogeneous catalysts of the Ziegler type consist of heterogeneous blocks of isotactic and atactic polymers rather than polyblends.