极性润滑剂对滑石粉填充PP性能的影响

Influences of Polar Lubricants on Properties of PP Filled with Talcum Powder

以滑石粉(Talc)填充聚丙烯(PP)为研究对象,引入了两种不同结构的酰胺类极性润滑剂,其结构分别为AB(A代表极性锚固基团;B代表长支链或直链烷烃)型和BAB型,考察了两者对PP/Talc复合材料力学性能和流变行为的影响,同时借助仪器化冲击,着重研究了极性润滑剂对材料冲击过程中裂纹产生功和裂纹扩展功的影响。结果表明,润滑剂的引入对流变行为影响较小,随着润滑剂添加量的增加,复合材料的熔体流动速率有所提高,加工性能改善,弯曲弹性模量和断裂伸长率有小幅度升高。BAB型润滑剂对PP/Talc复合材料具有更优异的增韧作用,实验范围内低温(0℃)缺口冲击强度最高提高了35%,冲击韧性提升主要得益于裂纹扩展功的增加。此外,扫描电子显微镜结果显示,BAB润滑剂的引入有利于改善Talc在PP基体中的分散均匀性,从而提高复合材料的冲击韧性。

Two different amide polar lubricants were introduced in talcum(Talc)filled polypropylene(PP)system,the structures of the two lubricants are AB(A:polar groups;B:long-branched or straight chain alkanes)and BAB type,individually.The influences of the two lubricants on mechanical properties and rheological behaviors of PP/Talc composite were investigated.In the meantime,the instrumented impact testing was employed to study the effects of BAB and AB lubricants on crack generation and propagation energy of the composite in the process of impacting.The results prove that the introduction of lubricants has little effect on the rheological behavior of PP/Talc composite,the melt flow rate increases with increasing lubricant content,showing better processability,flexural modulus and elongation at break are slightly improved.BAB lubricant shows better toughening effect for PP/Talc composite,the notched impact strength at 0℃increases by 35%maximally within the experimental range,and the improvement of toughness is mainly attributed to the increase of crack propagation energy.Besides,scanning electron microscope result shows that the dispersion uniformity of Talc in PP matrix is improved by introducing BAB lubricant,thus the toughness of the composite is improved.