Crystallization of Syndiotactic Polystyrene Monitored by Angular Distributions of Polarized Fluorescence

Abstract

The method to measure polarized fluorescence by rotating a sample around the excitation light (PFR) was applied to observe the initial stage of crystallization of syndiotactic polystyrene (SPS) induced by the exposure of naphthalene (NP) vapors. At room temperature, no crystallization of SPS appeared when the stretched films were exposed by NP vapors. PFR clearly evidenced that the NP molecules were not distributed uniformly but rather with a sort of orientation in the oriented amorphous SPS. NP molecules were clathrated in SPS films in the case of the exposure at 80°C. However, the exposure of NP vapors at 60°C was found to produce SPS/NP clathrate cocrystalline structure with only a small amount but rather mainly produce a trans-planar mesomorphic phase. In this initial stage, the wide angle X-ray diffraction revealed diffuse and unclear, whereas PFR was effective to determine orientation and distribution of the NP molecules. The NP molecules staying in the amorphous region were shown to be oriented due to the formation of a trans-planar mesomorphic phase, and their main arrangements were first determined by PFR.

Keywords:

• Clathlate structure
• Crystallization
• Naphthalene
• Polarized fluorescence
• Syndiotactic polystyrene
• Stretching
• Wide angle X-ray diffraction

ACKNOWLEDGMENTS

This work was supported by Grant-in-aid for Scientific Research (C) (21550206) from the Ministry of Education, Science, Sports and Culture of Japan. The research was partially carried out at the Center for the Instrumental Analysis, Shizuoka University.