Study On Crystallization And Mechanical Properties Of Pp/pet Blend

Polypropylene(PP) is selected as matrix, poly(ethylene terephthalate) (PET) as dispersed phase and NA-11 as the appropriate crystal nucleating agents(NA-11). First, the NA/PET/PP and PET/PP were blended in a twin-screw extruder in different orders. Subsequently, the NA/PET/PP composite is processed by injection molding, and then we analyze the crystallization behavior of the blends and test the mechanical property. In this experiment, we preliminary research the distribution and migration of NA on the two-phase interface of PP / PET blends.The mechanical properties such as tensile strength ,flexural strength, impact strength of PP/PET blends were also studied; thermal behavior, kinetic of nonisothermal crystallization of PP phase in the blend were investigated by using DSC.The result shows that crystallization temperature increases with the content of PET , until the content of PET reach 10%.the tensile, flexural and impact strength of the composite increase with the content of PET until the content of PET reach 20%; Compared with the mechanical properties of pure PP/PET blends, the mechanical properties of NA/PP/PET blends have been increased too much, the breaking strength have been increased about 30%,and impact strength about 400%; In different orders of subjecting, the improvement of the mechanical properties of the group added NA in injection molding process is slightly lower than that of the blend added NA in PET. The reason is that, the ability that NA catch PET melt droplets is so diversity in different circumstances.