Preparation, Structure And Performance Of EPDM/PP Thermoplastic Elastomer By Dynamic Vulcanization Based On Vane Extruder

EPDM/PP thermoplastic elastomer, with good insulation, impact resistance,heat-resistance, weather fastness, UV resistance, and easy machining, was widely used inautomobiles, home appliances, cables and wires, sports facilities, architecture and so on.Dispersion form of rubber particles is the key factor to the final performance of EPDM/PP.Rubber particles dispersed in matrix is not only related to its properties, vulcanization system,but also depends on the type of processing flow. Compared with shear flow field, extensionalflow field is more effective for dispersion and less limited to material viscosity ratio, however,it is difficult to realize with the existing equipment. The vane extruder achieved the wholeprocess of polymer processing through a series of convergence-expansion units based onextensional flow for the first time.EPDM/PP thermoplastic elastomer was prepared by vane extruder based on elongationalflow. The results were compared to that processed by shear flow, revealing the effect ofelongational flow on the structure and performance of composite. The results reveal thatunder the elongational flow in vane unit the composite has smaller and narrower particledistribution, higher crosslinking density, worse crystal texture, smaller crystallinity and bettercompatibility, ultimately demonstrating better mechanical performance.EPDM/PP with the rate of50/50was prepared by vane extruder, and the influence ofprocessing temperature, rotation speed and die diameter on the material structure andperformance was researched. The result shows that compared with the die diameter, thecrosslinking density of the material is more sensitive to processing temperature and rotationspeed. The influence of process parameters on the melting point of materials is smaller, but onthe crystallinity and crystal morphology is opposite bigger, the influence of rotation speed ismore obvious among these process parameters. Tensile strength, tear strength and elongationat break are greatly influenced by the process parameters, however，hardness is mainlydepended on the rate of rubber and plastic.