| Dynamic vulcanization is an effective method of preparing thermoplastic elastomer.Because of its good performance,thermoplastic elastomer made by dynamic vulcanization is looked as one of the useful polymer materials. With the development of automobile industry as well as chemical industry, much more requirements of the polymer materials product especially in cars are increasing in order to achieve the lightened deadweight and improved safety and comfort of cars. Based on the analysis of the imported cars sealing strip sample and domestic raw materials market survey, in the thesis, the object of the research is to design a kind of cars sealing strip material to meet the American standard taking the background of the domestic production of cars sealing strip sample. The effects of EPDM/PP blend ratio, peroxide curing systems, silica, silane coupling agent, processing aids, hyperbranched polyamide ester (HBPAE) on the rheological property, mechanical property, thermal property and hardness of EPDM/PP blends were studied.Conclusions are listed as follows:(1) The blends based on EPDM/PP which prepared by dynamic vulcanization with other additives, improved the propertys in comprehensive fields.(2) The EPDM/PP blended TPV with smooth surface, good flowability, smaller extrusive swelling ratio, good physical and mechanical properties and low cost was obtained by the choice of suitable peroxide curing system and modified silica. Experimental results showed the optimal ratios of modified silica 20 portions and peroxide curing system with DCP 1.5 portions and sulfur 0.2 portion.(3) Effects of addition agents on the dispersities of EPDM/PP/SiO2 blends were investigated by rotary rheometer and scanning electron microscope. The results showed that the effective dispersedness of the fillers in the EPDM/PP blends was increased gradually with the increase of the paraffin oil amount. The dispersion effect of the filler in the system was better with the introduction of the silane coupling agent KH-570 than with Si-69 with same amount. Furthermore, hyper-branched polyamide ester, which was similar to the "bridge" role of the silane coupling agent, was efficient to improve the dispersion effect of the filler particles in EPDM/PP blends.(4) Effects of the silane coupling agent on the mechanical properties of vulcanized EPDM/PP/SiO2 compounds were investigated by a universal testing. The experimental results revealed that the various properties of the blends were significantly improved using coupling agent-modified silica, such as greatly increased hardness, tensile strength and 100% stretch stress, as well as much declined compression permanent deformation and elongation at break. Moreover, it also can seen that the coupling efficiency of Si-69 was better than KH-570.(5) Effects of the silane coupling agent on the thermal deformation temperature of vulcanized EPDM/PP/SiO2 blends were studied. The results showed that the thermal deformation temperature was obviously increased with the addition of silane coupling agent. Si-69 coupling agent was more conducive to increase heat deformation temperature than KH-570 coupling agent.(6) One-pot synthesis of the EPDM/PP blend was described by mixing various raw materials with additives into the blender onetime on the basis of the research on the conditions of injection molding technology. The best parameters of twin-screw extruder in the experimental process of injection molding were also found.(7) Dynamically vulcanized EPDM/PP thermoplastic elastomer, which satisfied the American cars seal materials standard Materials was produced successfully. The experimental results showed that the development of the dynamically vulcanized EPDM/PP thermoplastic elastomer can replace the imported materials in the similar type. |
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