Crystallization of Syndiotactic Polystyrene in β-Form. 1. Positional Identification of Stacking Faults in the Solution-Grown Single Crystals

• Published in: Macromolecules Vol. 30; no. 14; pp. 4132 - 4136
• Main Authors: Tosaka, Masatoshi, Hamada, Noritaka, Tsuji, Masaki, Kohjiya, Shinzo, Ogawa, Tetsuya, Isoda, Seiji, Kobayashi, Takashi
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 14-07-1997
• Subjects: Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Properties and characterization; Structure, morphology and analysis; Dark field microscopy; Beta form; Transmission electron microscopy; Defect localization; Stacking fault; Styrene polymer; Solution crystallization; Experimental study; Syndiotactic polymer; Isothermal crystallization; Single crystal
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma970024z

The locations of the stacking faults in β-form single crystals of syndiotactic polystyrene, which were grown isothermally from a dilute solution at temperatures ranging from 150 to 210 °C, were identified in high-resolution and dark-field (DF) images taken by transmission electron microscopy. The shift or kink of the (210) lattice fringes, which shows the position of the fault, was directly detected in the high-resolution images. DF images taken using several reflections exhibited irregularly spaced striations parallel to the b-axis. Computer simulation of DF images based on the structural model of the stacking fault well supported the view that each striation corresponds to the position of the fault. The striations extended continuously and were very long, and accordingly, it was proposed that the stacking fault influences the attachment of a new polymer stem onto the lateral growth face which is not parallel to the bc-plane, resulting in irregular fold-surfaces of the single crystals.