アイオノマー特有の吸熱ピークの熱処理による変化

抄録

This study investigates the characteristic endothermic peaks of ionomers, T_i, appears at lower temperature than the melting point. We evaluate the thermal properties of ionomers under various heat treatment conditions with DSC. The T_i peak temperature and endothermic peaks area increase with longer heat treatment time. For more detailed analysis, we evaluate the nanoscale structure with small-angle and wide-angle X-ray scattering measurements. The correlation length between polyethylene crystals increases with increasing temperature above T_i. The results showed that the T_i peaks are very sensitive to heat treatment conditions, especially to the nanoscale structure. Furthermore, the radius of core of ion-aggregates and that of the immobile polymer layer was very sensitive of temperature. From these results, precise analysis also showed that the change in T_i peaks is due to the important role of molecular motion in the amorphous regions between crystals. We also showed that the appearance of T_i peaks depends on the interaction of ions with the carboxylic acid ion of polymers.