碱式硫酸镁晶须和滑石粉复合增强改性聚丙烯

Properties of MOSw/Talc Reinforced Polypropylene

以聚丙烯(PP)树脂为基体,加入不同质量比的碱式硫酸镁晶须(MOSw)和滑石粉(Talc)填料,通过双螺杆挤出机熔融共混制得MOSw/Talc复合增强PP基复合材料。考查MOSw/Talc质量比对复合材料力学性能、微观形貌、线膨胀系数和成型收缩率等性能的影响。结果表明,MOSw和Talc质量比为15/5时,复合材料具有较好的综合物理力学性能和最好的尺寸稳定性,在填料质量分数均为20%的条件下,与纯Talc填充PP基复合材料相比,其熔体流动速率提高8.8%,密度降低2.0%,拉伸强度、弯曲强度、弯曲弹性模量、缺口冲击强度和硬度分别提高8.2%,7.5%,34.5%,22.3%和13.5%,其线膨胀系数和成型收缩率数值分别为35.97×10^(–6)℃^(–1)和0.48%,接近或低于部分工程塑料。从微观形貌分析,MOSw和Talc几乎与基体流动方向相平行,取向排列较整齐,同时MOSw与PP基体间的界面没有产生相分离,表现出较好的界面相容性能。

By adding basic magnesium sulfate whisker(MOSw)and talcum(Talc)filler to the polypropylene(PP)resin matrix,the MOSw/Talc reinforced PP composites were prepared by melt blending in a twin-screw extruder.The effects of MOSw/Talc mass ratio on the mechanical properties,microstructure,coefficient of linear expansion and molding shrinkage of the composites were investigated.The results indicate that,when MOSw/Talc mass ratio is 15/5,the composite has the better comprehensive physical and mechanical properties and best dimensional stability,under that the mass fraction of fillers is 20%,compared with the pure Talc filled PP composite,the melt flow rate increases by 8.8%,the density decreases by 2.0%,the tensile strength,flexural strength,flexural modulus,notched impact strength and hardness increase by 8.2%,7.5%,34.5%,22.3%and 13.5%respectively,while its coefficient of linear expansion and molding shrinkage are 35.97×10–6℃–1 and 0.48%respectively,close to or lower than those of some engineering plastics.From the microscopic morphological analysis,MOSw and Talc are almost parallel to the flow direction of the PP matrix,and are aligned neatly.Meanwhile,there is no phase separation between the MOSw and the PP matrix,which shows good interface compatibility.