一种大分子改性剂对纳米SiO_2的改性及其在PU中的应用

Modification of Nano-silica with Self-regulating Macromolecular Modifier and Its Application in Polyurethane

采用自制的大分子表面改性剂(MAA)m-(BA)n-NCO对纳米SiO2进行表面改性,对改性前后的纳米SiO2进行FTIR、TGA、粒径分析表征。结果表明,大分子改性剂和纳米SiO2的表面发生化学键合,有效地阻止了纳米SiO2的团聚。用改性后的纳米SiO2制备了纳米SiO2/聚氨酯(PU)复合材料,SEM观察到纳米SiO2颗粒在PU中分散良好,XRD检测表明纳米SiO2阻碍了PU分子硬链段有序排列。力学性能检测显示纳米复合材料的力学性能有明显提高,当SiO2的用量为3%时,复合材料的断裂伸长率和拉伸强度均达到最大值,分别为458%和80.4 MPa。

A self-regulating macromolecular modifier was （MAA） m- （BA） n-NCO used for the modification of nano-SiO2, and the native and modified nano-SiO2 were investigated by FFIR, TGA, and DLS. The results indicated that the macromolecular modifier was bonded on the surface of nano-SiO2particles by chemical bond, and thus effectively prevented aggregation of SiO2 particles. Nano-SiO2/Polyurethane （PU） composites were synthesized by modified nano-SiO2. The analysis of SEM showed that these nano- SiO2 particles presented a perfect distribution character in the PU. The results of XRD approved that nano-SiO2 retarded the orderly arrangement of hard segment of PU molecule. The tensile properties of the composites were more excellent compared with those of PU filled with native SiO2, and when the mass fraction of modified nano-SiO2 arrived at 3%, the elongation at break and tensile strength reached the maximum, 458% and 80.4 MPa, respectively.