STUDY ON SPHERULITE MORPHOLOGY OF SYNDIOTACTIC POLYSTYRENE AND ITS FORMATION CONDITIONS IN ISOTHERMAL CRYSTALLIZATION

The spherulite morphology of syndiotactic polystyrene and the formation condition in isothermal crystallization have been studied by the polarizing microscope.There are eight kinds of spherulite formed as crystalline temperature( T c)changed from 200℃ to T m.The spherulite is feathered and the lamellae structure is bulking as T c lower than 240℃.The feathered spherulite is positive as 230℃ T c220℃ and becomes optically posifive negative mixed as 240℃ T c230℃.In addition,the shish kebab and four sectional positive spherulite with a helical matting ring can form when crystallized isothermally near 230℃.Most spherulites crystallized at T c240℃ are eight sectional,the distribution of the eight sections varies with the rotation of the samples.There are also very few Four sectional positive and negative spherulites which coexist with the eight sectional spherulites as T c240℃ and T c250℃,respectively.