1. Advanced Polymeric Materials Engineering, Graduate School of Engineering, Toyota Technological Institute, Hisakata 2-12-1, Tempaku, Nagoya 468 8511, Japan, Unitika Ltd., Kozakura 23, Uji, Kyoto 611-0021, Japan, and Nagoya Municipal Research Institute, Rokuban 3-4-41, Atsuta, Nagoya 456-0058, Japan