Crystallization of Syndiotactic Polystyrene in β-Form. 4. Crystal Structure of Melt-Grown Modification

The propriety of the theory presented in the authors' previous paper [Tosaka et al. Macromolecules 1997, 30, 6592], which predicted that monoclinic crystallites are the majority in the β‘-modification of syndiotactic polystyrene, was assessed by examining the structure of the modification. The electron diffraction patterns from the single-crystal-like lamellae of β‘-modification showed a streaked feature which supports our prediction. The high-resolution images evidenced that the β‘-modification is composed of monoclinic domains; the boundary between the domains is a twin plane. This feature was also detected in the dark-field images as irregularly spaced striations. The probability, p, to find the same type of bimolecular layer (viz., a motif) at the next position of a motif was estimated from the high-resolution and the dark-field images. The subsequent energetic analysis based on the experimental p values showed that the theory presented in the previous paper is reasonable.