【作者】 战仁波；

【导师】 黄丽；

【作者基本信息】 北京化工大学 ， 材料学， 2005， 硕士

【摘要】 本论文采用熔融共混法制备聚丙烯（PP）/纳米SiO₂复合材料,研究了纳米SiO₂的表面处理方法、含量等因素对复合材料的力学性能（拉伸强度、冲击强度）、结晶特性及其动力学的影响规律,并通过试样的缺口冲击断面形貌分析,对其增韧增强机理作了初步探讨。 本论文采用超声波分散、硅烷偶联剂处理和分散剂与偶联剂复合处理的方法对纳米SiO₂进行表面改性,通过双辊熔融共混以及硫化机压片的方法制备了PP/纳米SiO₂复合材料,系统研究了表面处理方法、纳米SiO₂含量等因素对复合材料的力学性能的影响规律。研究结果表明:经分散剂与偶联剂复合处理的纳米SiO₂对聚丙烯有较显著的增韧效果。 通过偏光显微镜观察了PP和PP/纳米SiO₂复合材料的晶体结构;用DSC法研究了PP/纳米SiO₂复合材料在不同纳米粒子含量时的结晶特性。结果表明:纳米SiO₂对PP具有异相成核的作用,使PP的结晶温度和结晶速度提高,球晶尺寸变小,完善程度降低。 用DSC方法研究了PP/纳米SiO₂复合材料的非等温结晶动力学。用修正Avrami方程的Jeziorny法、Ozawa法和Mo法进行处理,表明Jeziorny法和Mo法处理非等温结晶过程比较理想。不同降温速率下的成核机理基本不变。降温速率越快,单位结晶时间达到的相对更多还原

【Abstract】 Polypropylene （PP）/nano-SiO₂ composites had been prepared by melt-blending process in this paper. The effect of surface treatment methods and content of nano-SiO₂ on the mechanical properties （tensile strength, impact thoughness） and crystallization property of composites were investigated. The structural morphology had been studied by scanning electron microscopy （SEM）, and discussed the toughness and reinforcement mechanism nano-SiO₂ on PP.The surface of nano-SiO₂ was modified by ultrasonic dispersion, silane coupling agent and both dispersant and silane coupling agent in this paper. And PP/nano-SiO₂ composites were prepared by melt-blending process. The effect of surface treatment methods and content of nano-SiO₂ on the mechanical properties of composites were systematically investigated. The results show that the nano-SiO₂ which is modified by dispersant and silane coupling agent has a distinct effect on the toughness of PP.The crystal structure of PP and PP/nano-SiO₂ composites were studied and observed by Polarizing Microscope; The crystal charac-更多还原