The effect of heat treatment on the microfibrillar network of poly(p-phenylene benzobisthiazole)

• Published in: Polymer engineering and science Vol. 36; no. 10; pp. 1355 - 1359
• Main Authors: Cohen, Yachin, Gartstein, Efim, Arndt, Karl-Friedrich, Ruland, Wilhelm
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.05.1996; Wiley Subscription Services; Society of Plastics Engineers, Inc; Blackwell Publishing Ltd
• Subjects: Analysis; Applied sciences; Crystallization; Exact sciences and technology; Fibers and threads; Forms of application and semi-finished materials; Mechanical properties; Polymer industry, paints, wood; Polymers; Technology of polymers; Heat treatment; Phenylene derivative polymer; Morphology; Benzothiazole derivative polymer; Microfibril
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.10530

Materials exhibiting exceptional mechanical properties can be fabricated from rigid polymers. In a spinning process, an oriented solution is solidified by the action of a nonsolvent, which induces crystallization of an oriented rigid polymer. Drying and heat treatment result in the final material having the desired properties. The effect of heat treatment on the morphology of poly(p‐phenylene benzobisthiazole) (PBZT) films was studied by measurements of small‐angle X‐ray scattering (SAXS) and wide‐angle X‐ray diffraction (WAXD). Films were formed by coagulation in water. The wet films were dried with supercritical CO2 to maintain an open network structure. Coagulation in water resulted in formation of microfibrils having diameter of ∼9 nm. Heat‐treatment at 600°C caused significant coalescence of microfibrils. The crystallite size was increased by heat treatment from a value that is smaller than the microfibrillar diameter indicating defects in chain packing, to a value comparable to the microfibrillar diameter.