1. State Key Laboratory of Chemical Resource, Engineering & Key Laboratory of Carbon Fiber and Functional Polymer, Ministry of Education, Beijing University of Chemical Technology; 15 Beisanhuan East Road, Chaoyang District Beijing 100029 P.R. China
2. College of Polymer Science and Engineering, Sichuan University; Chengdu 610065 P.R. China
3. Department of Organic and Polymeric Materials; Graduate School of Science and Engineering, Tokyo Institute of Technology; 2-12-1 Ookayama Meguroku Tokyo 152-8552 Japan