1. College of Materials Science and Engineering, The Key Laboratory of Material Processing and Mold of Ministry of Education, Zhengzhou University, Zhengzhou, China;2. Institute of Polymer Materials, Friedrich‐Alexander University Erlangen‐Nuremberg, Erlangen, Germany;3. School of Materials and Chemical Engineering, Henan University of Engineering, Zhengzhou, China;4. China Astronauts Research and Training Center, Beijing, China
Abstract:
The mechanical properties and microstructure of injection molded isotactic polypropylene parts with high orientation before and after annealing are analyzed. The mechanical properties of the annealed samples are improved effectively. Through thorough analysis of various structural characterizations, a microstructural model based on the fact that the total length of long period kept constant to analyze the variation of mechanical properties is proposed. It is suggested that the increase of overall crystallinity, the recombination of crystalline phase, and the increase of amorphous phase, respectively, are beneficial for the improvements of the strength, stiffness, and toughness of annealed samples.
