1. National Engineering Research Center of Flame Retardant Materials, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
2. CAS Key Laboratory of Space Manufacturing Technology, Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences, Beijing 100094, P. R. China
3. Beijing Chenjing Electronics Co., Ltd., Beijing 100015, P. R. China
4. Laboratory of Polymer Materials and Engineering, NingboTech University, Ningbo 315100, P. R. China