Study On Structure And Properties Of High Performance Polypropylene

The mechanical properties of polypropylene were improved byreactive blending with a few nylon6, polyethylene terephthalate, epoxyand compatibilizer. The morphology of PP/PA6 blends and PP/PET blends wereanalysized by ESEM and image processing software. The crosslink actionof epoxy in PP melt was studied in torque rheometer. The melt flow indexand dynamic contact angle of PP/EPOXY blends in water were measured.The isothermal crystalline state of PP/PA6 blends, PP/ PET blends andPP/EPOXY blends were observed by polarizing microscope and theirmechanical properties were also tested. At last, the mechanical propertiesof the three systems were contrasted. PP/PA6 is a typical immiscible system. The compatibility wasimproved by adding two kinds of compatibilizer, and EPDM-g-GMA wasmore efficient. The dimension of PP spherulites minished with PA6content increasing. PA6 phase distributed among PP spherulites, and thecompatibility was improved by adding PP-g-MAH or EPDM-g-GMA. Thereactive compatibilization and rubber tougheness had cooperativeeffectiveness on PP/PA6 blends, after adding EPDM-g-GMA. The Yang'smodulus of PP/PA6 blends was improved after adding PP-g-MAH, at thesame time, the yield stress was higher than that of immiscible system. PP/PET is also a typical immiscible system. The compatibility wasimproved by adding two kinds of compatibilizer, and EPDM-g-GMA wasmore efficient. The dimension of PP spherulites minished after PP hadblended with PET . PET phase distributed among PP spherulites, and thecompatibility was improved by adding EPDM-g-GMA. PET crystal phasebecame finer after adding nucleating agent in PP/PET/EPDM-g-GMAblends. The reactive compatibilization and rubber tougheness hadcooperative effectiveness on PP/PET blends, furthermore, nucleatingagent takes advantage in improving toughness. The Yang's modulus ofPP/PET blends was improved after adding PP-g-MAH, at the same time,the yield stress decrease slowly.Epoxy was likely to begin gelationization, which lift torque curve in10~15minute, and then Epoxy come into solidify period. After PP blendswith epoxy, the crystallization was baffled by crosslinking and thedimension of PP spherulites become small and illegible, at the same time,the hydrophilicity increase and the fluidity descend. The Yang's modulusof uncompatibile system increase while the yield stress and toughnessdecrease. After adding PP-g-MAH, the Yang's modulus of blend increasemore, and the yield stress increase slowly and toughness improve. The results of mechanical properties contrasting show thatPP/PA6/EPDM-g-GMA system was toughest, PP/PET/PP-g-MAH systemwas rigidest and PP/E-51/ 203#/PP-g-MAH system is best at yield stress.