滑石、CaCO_(3)、BaSO_(4)填充PP复合材料力学性能及界面相互作用对比

Comparison of mechanical properties and interfacial interactions of polypropylene composites filled with talc,calcium carbonate,and barium sulfate

以3种白色矿物粉体[颗粒状CaCO_(3)、BaSO_(4),片层状滑石(talc)]为填料,聚丙烯(PP)为基体树脂,通过熔融共混法制备PP复合材料,研究3种矿物粉体在不同含量时对PP复合材料的力学性能、流动性能与断裂形貌的影响规律,并采用Turcasanyi半经验公式计算了矿物填料与PP复合材料力学性能界面相互作用。结果表明,3种矿物粉体的加入均降低了PP的拉伸强度,PP/talc复合材料的拉伸强度明显高于PP/CaCO_(3)与PP/BaSO_(4),且talc的加入明显增强了PP的拉伸模量与弯曲模量;CaCO_(3)与BaSO_(4)的加入使复合材料弯曲强度降低,talc的加入使复合材料弯曲强度提高;CaCO_(3)对PP断裂伸长率与悬臂梁缺口冲击强度的提升最为明显;talc的加入使复合材料流动性能得到提高,而颗粒状的CaCO_(3)与BaSO_(4)的加入对加工性能影响较小;CaCO_(3)与BaSO_(4)在PP中均存在一定团聚现象,且与PP相容性较差,存在明显界面缺陷;talc与PP间界面较模糊,二者之间有较强的黏结作用。

Polypropylene(PP)⁃matrix composites were prepared through melt blending with three types of white mineral powders including granular calcium carbonate(CaCO_(3))and barium sulfate(BaSO_(4))and lamellar talc as fillers.The effects of three types of mineral powders on the mechanical properties,flow properties and fracture morphology of the resultant composites were investigated.In addition,Turcasanyi formula was used to calculate the interface interaction between the PP matrix and mineral fillers.The results indicated that the composites showed a decrease in tensile strength with the addition of mineral powders.The tensile strength of the PP/talc composite was significantly higher than those of the PP/CaCO_(3)and PP/BaSO_(4)composites.The addition of talc significantly enhanced the tensile and bending moduli of PP and also increased its bending strength.However,the addition of CaCO_(3)and BaSO_(4)reduced the bending strength of PP.CaCO_(3)exhibited the most obvious effect to improve the elongation at break of PP and the notch impact strength of cantilever beam.The addition of talc improved the fluidity of the composites,whereas the addition of granular CaCO_(3)and BaSO_(4)showed few effects on the process ability.CaCO_(3)and BaSO_(4)were agglomerated in PP due their poor compatibility with PP and obvious interface defects.The interface between talc and PP was vague,and there was a strong bonding effect between talc and PP.