STRUCTURAL PHASE TRANSITIONS OF CRYSTALLINE POLYMERS VIEWED FROM THE WAXD/SAXS AND VIBRATIONAL SPECTRAL MEASUREMENTS

摘要

Crystalline polymers exhibit various types of phase transitions when they are subjected to such an external field as temperature, stress, solvent atmosphere, etc. In order to clarify the structural changes during these phase transitions and to reveal the transition mechanisms from the molecular level, we need to collect the experimental data viewed from the different directions. Sometimes it is useful to perform the simultaneous measurements of various different kinds of techniques so that the complicated structural changes can be clarified in detail. In our laboratory we have developed the system by which the simultaneous measurement of wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) and Raman spectra can be made during the heating process, for example. In the present paper we describe some case studies about the phase transitions investigated by an organized combination of WAXD, SAXS (and Raman) techniques for several typical polymers.