Kinetics of melting and characterization of the thermodynamic and kinetic properties of syndiotactic polystyrene

✍ Scribed by A. Sorrentino; R. Pantani; G. Titomanlio

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 545 KB
• Volume: 45
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/polb.21039

✦ Synopsis

Abstract

A study of the crystallization process of syndiotactic polystyrene is carried out, with particular emphasis on the effect of previous melt annealing on the subsequent crystallization kinetics and polymorphism, with a combination of thermal analysis, infrared spectroscopy, and X‐ray diffraction. An effort is made to obtain quantitative results in terms of the relative crystallinity content of the α and β phases after a given thermal treatment. A kinetics of melting for the crystalline memory is proposed, which enables the determination of the time at a given temperature that ensures the complete fusion of the α crystals. This leads to a generalization of the effects of the time–temperature couple on the memory effect. A particular protocol is identified, which upon solidification from the melt induces the development of just one crystalline phase, either α or β. This allows the determination of the enthalpy of crystallization, the maximum attainable crystal volume fraction, the crystallization half‐time as a function of temperature, and the Avrami index for each of the two crystalline phases. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 196–207, 2007