The crystallization characterization of bulk syndiotactic polystyrene sample: immediate evidence from IR spectroscopy

Abstract

The crystallization characterization of bulk syndiothactic polystyrene (s-PS) sample is thoroughly studied using the Fourier transform infrared spectroscopy (FTIR). The WAXD is further used to identify the s-PS crystal formation to confirm the specific absorbance in FTIR spectra. Both melt and cold-crystallization behavior are quantitatively determined using FTIR spectra ranging from 870 to 820 cm(-1) at 264 degreesC. Fitting curves to IR spectra provides direct evidence of bulk s-PS crystallization behavior in quantification. The melt-crystallization process yields the beta-form only; while the cold-crystallization process yields both the alpha and the beta-form crystal in bulk s-PS sample. The beta-form crystal is generated from the phase-transformation of the alpha-form crystal by cold-crystallization process, the alpha-form crystal is the initial phase. The activity energy of the alpha-form formation is lower that that of the beta-form, suggesting that the alpha-form crystal is kinetically favorable while the beta-form crystal is thermodynamically favorable. (C) 2003 Published by Elsevier Ltd.