Study On Properties And Preparations Of Blending Thermoplastic Elastomer-epdm/pp

EPDM/PP thermoplastic elastomer was widely used in automobiles, electronics, electrical, architecture, sports facilities and so on with good weatherfastness, ozone resistance, UV resistance, heat-resistance, insulation, impact resistance, and easy machining, in abroad. But PVC materials that were not environmentally friendly were still used in domestic, and it was obviously deficient for the research of EPDM/PP thermoplastic elastomer. Therefore, the research had become an urgent need.The paper described some preparations of blending EPDM/PP thermoplastic elastomer. There were several kinds of mill mixer, RM-200A rheometer equipment, single-screw extruder and pressing machine which were used in the performance. In order to determine the preparation process of EPDM/PP thermoplastic elastomer, the advantages and disadvantages of these equipments were discussed in detail. The further work was carried out about the mechanical properties of materials for TPVs with the preparation methods which had been determined. With different proportion of rubber and plastics, these mechanical properties were compared. In order to further strengthen mechanical properties of materials, different kinds of short glasses fibers were introduced. At the same time, in order to improve bad compatibility of EPDM and PP, the compatibilizer Ethylene-vinyl acetate (EVA), maleic anhydride and polypropylene grafted with maleic anhydride were researched. In addition, in order to further understand material properties, the performances of heat aging, solvent resistance, crosslinking density, thermogravimetic, micro crystal structure and surface morphology were also examined.Results showed that EPDM/PP thermoplastic elastomer had good performances by using opening mixer and molding. When the ratio of EPDM/PP was 60/40, the materials had the best comprehensive mechanical performance. The mechanical properties of PP/EPDM composites were greatly strengthened by short glass fibers (SGF). The function of compatibilizer (EVA) is obvious on the ratio of 75/25. It was obviously that tensile strength on 75/25 and elongation at break on 60/40 were both improved with the content of compatibilizer (MAH) increasing. Adding polypropylene grafted with maleic anhydride was able to obviously increase tensile strength of TPVs, and existed the maximum of tear strength for TPVs.Results showed that the mechanical properties of the TPVs changed in 5%. Therefore, TPVs had good performance of aging resistance and moisture resistance. In addition, TPVs inherited solvent resistance performance of rubber EPDM material, and decreased with increasing the ratio of rubber EPDM in TPVs. With the ratio of rubber phase increasing, the crosslinking density of TPVs gradually decreased. As a result of increasing the content of PP, the heat-resisting performance of TPVs would decrease. XRD showed that the existence of EPDM rubber phase hampered the movement of PP molecular chain in a certain extent, lowered the crystallinity of PP phase, and changed the micro crystal structure of the PP plastic phase. However, when the content of PP phase was more than 50%, the limit of EPDM rubber phase was disappeared. Scanning electron microscope showed that with the increase of PP, the aggregation of PP plastic phase was more and more obvious. When the ratio of EPDM/PP is 50/50, the aggregation of PP phase presented obvious slice layer structure, and the mechanical properties of TPVs would decrease, obviously.