纳米SiO2改性UHMWPE性能的研究

文中研究了纳米SiO₂填充改性超高相对分子质量聚乙烯(UHMWPE)塑料的耐热性能。结果表明：在UHMWPE中添加少量经偶联剂表面处理的纳米SiO₂对材料的耐热性能有较显著影响。用DSC法研究了UHMWPE/纳米SiO₂复合材料在不同纳米粒子含量时的熔融结晶行为。纳米SiO₂的加入，起到了结晶成核剂作用。通过偏光显微镜观察了复合材料结晶结构，同时和纯UHMWPE进行了比较。发现较低含量纳米SiO₂在UHMWPE中有成核作用，使UHMWPE以异相成核方式结晶，UHMWPE的结晶度提高，球晶颗粒变小。

Properties of UHMWPE-based composites filled with nano-SiO2

The effect of the nano-silica filled in the ultra-high molecular weight polyethylene (UHMWPE) on the resistance to heat was discussed. It is shown that the resistance to heat of UHMWPE are greatly affected by a small quantity of nano-silica, which is surface modified by coupling agent, so that the UHMWPE-based composites can be used in more fields. The fusion-crystal action of UHMWPE/nano-SiO_2 composites filled with varied contents of nano-SiO_2, which were prepared by compression molding process, was studied by means of Differential Scanning Calorimetry (DSC). It is showed that the filled nano-SiO_2 acts as a nucleating agent. The characteristics and crystal structures of UHMWPE/nano-SiO_2 composites were studied and observed by Polarizing Microscope, and were compared with that of the pure UHMWPE. The results show that a small quantity of nano-SiO_2 causes a nucleation in UHMWPE and the heterogeneous nucleation domains during the crystallization, and the crystallization degree is increased and the size of the crystals is decreased.