表面改性对聚丙烯/纳米氢氧化镁复合材料性能的影响

Effect of Surface Modification on Properties of PP Filled with Nano-Mg(OH)_2 Composites

研究了表面处理剂(钛酸酯和硅烷偶联剂)对聚丙烯/纳米氢氧化镁(MH)阻燃复合材料性能的影响。通过高压毛细管流变仪、LO I、力学测试、DSC和SEM对PP/纳米MH复合体系的结构与性能进行了研究。结果表明,所选偶联剂能有效地降低复合体系的表观黏度,改善体系的流动性。未改性的纳米MH对PP基体有异相成核作用;而表面改性剂能削弱填料对基体的异相成核作用。改性后的纳米MH粒子以独立形式均匀分散在基体中,PP与纳米MH界面的粘接力得到了加强,复合材料的拉伸性能和冲击强度有较大幅度的提高,阻燃性能也得到了改善。

Nano-magnesium hydroxide （MH）, which was modified by titanate and silane, respectively, was filled into polypropylene as a fire retardant. The effects of surface treatment on the structure and the properties of PP/MH composites were studied by rheological behaviors, mechanical tests, LOI, DSC and morphology studies. The results show that addition of nano-MH can improve flame retardancy of PP/MH composites, but deteriorate mechanical properties of composites. However, PP matrix filled with treated nano-MH can improve significantly tensile and impact strength of PP/MH composites and has little effect on flame retardancy and elongation at break of the composites. PP filled with treated nano-MH powders decreases melt viscosity of PP/MH composites, which improves their processing behavior. Nano-MH has heterogeneous nucleation on PP matrix and makes crystallization peak temperature increased. However, surface modifier can weaken heterogeneous nucleation of MH on PP/MH composites. Interfacial adhesion of PP/MH composites is significantly improved, as seen in morphology studies in the changed fracture mechanism.