TiO2-SiO2纳米复合颗粒改性形状记忆聚氨酯

Shape Memory Polyurethane Modified by Nano TiO_2-SiO_2 Composite Particles

利用分子量为3 000的聚己内酯二元醇作为软段,二苯基甲烷二异氰酸酯作为硬段用预聚体法合成了形状记忆聚氨酯,在合成过程中原位加入经KH550表面处理后的TiO2-SiO2纳米复合颗粒,制备了新型形状记忆聚氨酯/TiO2-SiO2纳米复合颗粒复合材料。采用傅里叶变换红外光谱、差示扫描量热、力学性能测试、扫描电镜、形状回复测试、循环形变记忆分析及偏光显微镜考察了改性形状记忆聚氨酯样品的力学性能和形状回复性能。研究结果表明:复合材料拉伸强度较纯SMPU提升90%,形状固定率Rs在90%左右,形状回复率Rf保持在94%以上,纳米颗粒的加入可以降低循环形变后损失的形状回复率。

Shape memory polyurethane modified by nano TiO2-SiO2 composite particles was synthesized by prepolymer polymerization. Poly（ε-caprolactone）（Mw = 3 000） was used as soft segment and diphenylmethane-4, 4＇-diisocyanate （MDI） as hard segment. The nano TiO2-SiO2 composite particles modified by 3-Aminopropyltriethoxysilane （KH550） were feded by in situ polymerization to prepare shape memory polyurethane（SMPU）/TiO2-SiO2 nano composite materials. The mechanical and shape memory properties were investigated using Fourier transform infrared spectroscopy （FT-IR）, differential scanning calorimeters （DSC）, tensile testing, scanning electronic microscope （SEM）, shape recovery test, cyclic shape memory test and polarizing microscope （POM）. Results showed that the tensile strength of SMPU/TiO2- SiO2 composite materials was increased by 90%. The shape recovery retention（Rs） was about 90% and the ratio of recovery（Rf） was higher than 94%. It was also found that the loss of Rf can be reduced with addition of nano TiO2-SiO2 composite particles.