磺酸型水性聚氨酯／改性SiO2复合材料的制备与性能研究

用硅烷偶联剂3-氨丙基三乙氧基硅烷（KH-550）对纳米二氧化硅（SiO2）进行改性，采用原位聚合将改性后的SiO2引入到磺酸型水性聚氨酯（WPU）中。结果表明，硅烷偶联剂与SiO2表面羟基发生了化学反应；随着改性SiO2含量的增加，复合材料的粒径逐渐增大，且复合材料的耐水性则得到明显改善；拉伸强度则随改性SiO2含量的增加先增大后减小，断裂伸长率逐渐减小；当改性SiO2质量分数为2．0％时，复合材料的拉伸强度最大，其值为39．62MPa，粒径为77．16nm，吸水率为13．69％，复合材料的综合性能较好。

Preparation and Properties of Sulfonated Waterborne Polyurethane/Modified Si02 Composites

The nano-silica particles were modified by silane coupling agent of 3-aminopropyl triethoxysilane （KH-550） , then sulfonated waterborne polyurethane/modified SiO2 were prepared by in situ method. The results showed that the surface hydroxyls of SiO2 were reacted with silane coupling agent. The particle size of the compos- ites increased with the contents of modified SiO2 increasing, but the water resistance was obviously improved, the tensile strength increased first and then decreased, the elongation at break decreased slowly. The tensible srenght of composites was the biggest and its value was 39.62 MPa, its particle size was 77. 16 nm and its water absorption was 13.69% when the mass fraction of modified SiO2 was 2. 0%. The composite performance was the better.