Study On Modifying Of Polypropylene

In these paper precious studies on the modifying of polypropylene have been reviewed. Chem-crosslinking of PP, β-nucleator modifying of PP, nano-silicate modifying of PP, ultrafine calcium carbonate modifying of PP have been studied with melt blending. Effect of many factors on the mechanical properties of PP has been discussed, and the mechanism of modifying has also been investigated from the micro-structure.The results of the study indicate: Chem-crosslinking can increase the mechanical properties of PP, the best content of initiator and crosslinking agent are 0.2%wt and 1.3%wt respectively; (3 crystal nucleator can improve izod impact strength of PP, With the content of β crystal nucleator is0.5%wt, its izod impact strength can excess 30KJ/m ,but tensile strength and tensile modulus will reduce. The data of XRD indicate: tensile, flexural and impact properties of PP match with the content of β-crystaHine. Heat treatment can also increase the mechanical properties of PP, Effect of TMB on the crystallization has been studied by DTA. With the content of 2%wt nano-silicate, tensile strength of PP is 35.67MPa, tensile modulus is 1.65GPa, flexural strength is 42.72MPa, flexural modulus is 1.07Gpa, izod impact strength is 11.25KJ/m2. nano-silicate can make PP form smaller the crystalline. With the content of 5%wt ultrafine calcium carbonate, tensile strength of PP is 33.68MPa, tensile modulus is 1.38GPa, izod impact strength is 9,38KJ/m2.