基于点击化学反应高分散纳米二氧化硅改性聚氨酯的制备与性能

将4,4′-二羟甲基-1,4-庚二炔作为扩链剂制备了侧链含有端炔基的聚氨酯(PU),然后基于铜催化的1,3-偶极环加成点击化学反应,将含有高接枝密度3-叠氮基丙基三乙氧基硅烷的纳米二氧化硅和炔基功能化PU反应,制备了高分散纳米二氧化硅改性PU复合材料。对PU纳米复合材料的断面形貌、热稳定性和耐溶剂性进行了表征。研究结果表明,基于点击反应制备的纳米二氧化硅改性PU中的纳米粒子分散良好,热稳定性和耐溶剂性显著增强。随着纳米二氧化硅含量的增加,PU复合膜的耐溶剂性和热稳定性逐渐增强;与纯PU相比,纳米二氧化硅质量分数为3%时,PU膜的最大分解速度下的温度提高了12℃,甲苯吸附率降低了586%。

Preparation and Properties of Highly Dispersed Nano-Silica Modified Polyurethane via Click Chemistry Reaction

The polyurethane(PU)bearing alkyne groups was firstly prepared by using 2,2-di(prop-2-ynyl)propane-1,3-dio(DPPD)as chain extender.Nano-silica modified PU composites were prepared via the copper-catalyzed 1,3-dipolar cycloaddition(CuAAC)click chemistry reaction between nano-silica with high grafting density of 3-azidopropyltriethoxysilane and alkyne-functionalized PU.The cross-sectional morphology,thermal stability and solvent resistance of PU nanocomposites were characterized.The results show that the nanoparticles are well dispersed in the nano-silica modified PU based on CuAAC click reaction,and the thermal stability and solvent resistance are significantly enhanced.With the increase of nano-silica content,the solvent resistance and thermal stability of the PU composite films were gradually enhanced.When the content of nano-silica is 3%in the PU nanocomposites,the temperature at the maximum decomposition rate is increased by 12℃,and the adsorption rate of toluene is reduced by 586%compared with pure PU.