BY ANGULAR DISTRIBUTIONS OF POLARIZED FLUORESCENCE

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 well clarified that the NP molecules were distributed not 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.