1. School of Chemical Engineering and Technology Tianjin University Tianjin 300350 China
2. School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University Tianjin 300350 China
3. Polyolefin Research Department Petrochina Petrochemical Research Institute Beijing 102206 China
4. Beijing Key Laboratory of Quality Evaluation Technology for Hygiene and Safety of Plastics Beijing Technology and Business University Beijing 100048 China