Studies On Preparation And Properties Of High Toughness Engineering Plastics Via Dynamic Vulcanization

In this paper, nylon 6 (PA6)/maleic anhydride grafted ethylene-propylene-diene rubber (EPDM-g-MAH), polyformaldehyde (POM)/EPDM-g-MAH, polyethylene terephthalate (PET)/glycidyl methacrylate grafted ethylene-propylene-diene rubber(EPDM-g-GMA) were prepared via dynamic vulcanization method. The main results are shown as follows.1. PA6/EPDM-g-MAH alloys were prepared via dynamic vulcanization method, and the effects of vulcanization system and its content, and rubber/plastics ratio on the properties of PA6/EPDM-g-MAH alloys were studied. The results of mechanical property measurement, scanning electron microscope (SEM), dynamic mechanical thermal analysis (DMA), thermogravimetric Analysis (TGA), X-ray diffraction (XRD)and differential scanning calorimetry (DSC) show that the dynamically vulcanized PA6/EPDM-g-MAH (80/20) blend with phenolic resin (PF) curing system and its content of 0.3 wt% possesses satisfactory properties. Its tensile strength and notched impact strength are higher than those of unvulcanized PA6/EPDM-g-MAH (80/20)blend by 69.5% and 128.8%, respectively, which is due to the improved compatibility between PA6 and EPDM-g-MAH via dynamic vulcanization. Moreover, the thermal stability of PA6/EPDM-g-MAH blends, crystallization temperature and crystallization rate of PA6 are also improved because of dynamic vulcanization.2. POM/EPDM-g-MAH alloys were prepared via dynamic vulcanization method,and the effects of vulcanization system and its content, and rubber/plastics ratio on the properties of POM/EPDM-g-MAH alloys were studied. The results of mechanical property measurement, SEM, DMA, TGA, XRD and DSC show that the dynamically vulcanized POM/EPDM-g-MAH (80/20) blend with sulfur (S) curing system and its content of 0.4 wt% has better comprehensive properties. Its notched impact strength is higher than that of neat POM and unvulcanized PA6/EPDM-g-MAH (80/20) blend by 188.3% and 78.2%, respectively, and its tensile strength is higher than that of unvulcanized PA6/EPDM-g-MAH (80/20) blend by 14.3%. Moreover, dynamic vulcanization can improve the thermal stability of POM/EPDM-g-MAH blends and crystallization rate of POM.3. EPDM-g-GMA was prepared by melt grafting, and PET/EPDM-g-GMA alloys were prepared via dynamic vulcanization method. The effects of vulcanization system,vulcanizing agent content and rubber content on PET/EPDM-g-GMA alloys were investigated. The results of mechanical property test, SEM, DMA, TGA, XRD and DSC show that the dynamically vulcanized PET/EPDM-g-GMA (70/30) blend with PF curing system and its content of 0.45 wt% possesses the best comprehensive properties.Its notched impact strength is higher than that of neat PET and unvulcanized PET/EPDM-g-GMA (70/30) blend by 594.5% and 66.2%, respectively, and its tensile strength is higher than that of unvulcanized PET/EPDM-g-GMA (70/30) blend by 19.4%. Moreover, dynamic vulcanization can also enhance the thermal stability of PET/EPDM-g-GMA blends and crystallization rate of PET.