Effect Of Modified Calcium Sulfate Whisker On Structure And Properties Of Polypropylene

This article uses the adipic acid(AA)to modify the anhydrous calcium sulfate whisker(ACSW)and hemihydrate calcium sulfate whisker(HCSW),and SEM,EDS,XRD and FTIR to explore the mechanism of modification.The results indicated that the crystal structures of two kinds of modified calcium sulfate whiskers have not been changed.AA and two kinds of calcium sulfate whiskers are combined with chemical reaction way,and generated cyclic compounds or adipic acid calcium attached on the surface of the calcium sulfate whisker.The effects of modified anhydrous calcium sulfate whiskers(MACSW)and modified hemihydrate calcium sulfate whiskers(MHCSW)on the ?-nucleation capability and mechanical properties of polypropylene(PP)were studied.(1)Crystallization properties: when with 15% MACSW(0.3%AA),PP composites have the largest crystallization temperature of 129.20?;the reults of XRD and POM analysis showed that AA,ACSW and HCSW had synergistic effects on the ?-nucleation of PP.(2)Mechanics performances: compared with the pure PP,the tensile strength of MACSW modified PP increased by 14.3%,the bending performance increased 29.3%,and the impact strength increased 1.4 times;the tensile strength of HCSW modified PP increased by 7.7%,bending strength increased 25.8%,and impact strength increased 1.21 times.The resluts indicated that MACSW modified PP could gain better effect to improve the mechanical properties of composites than MACSW modified PP.The analysis of the isothermal crystallization behaviors of PP composties modified with MACSW also showed that AA and ACSW have a synergistic effect on the nucleation of PP.