Abstract
The effects of formations of electron-donor-acceptor (EDA) complex in polymeric materials upon mechanical properties were studied for the linear and network polyurethanes containing phenylimino-group as donor unit which were complexed with p-chloranil in a 14-17% yield of the theoretical amount based on the assumption of formation of complex whose composition is donor : acceptor =1 : 1. Dynamic mechanical measurements were performed with Vibron-II at 35, 11, 0. 1, and 0.01 Hz over the temperature range from-90 to 100°C. An increase in the glass transition temperature (Tg) by 3-4°C and in the modulus in the temperature region above Tg, and further an appearance of the α' dispersion above Tg with the activation energy of 8. 8 kcal/mole were found as a result of complexing of the polyurethanes. These were interpreted in terms of the increased intermolecular interaction or the aggregation due to the introduced EDA complex in polymers. From chemical stress relaxation measurements of the complexed or the original polymers, the complexed polymeric materials were found to be degraded more easily in comparison with the original polymers by a long time exposure (up to 100 hrs) to large stress (20% elongation) under a high temperature such as 100°C.
