羧甲基纤维素纳米二氧化硅复合物制备及其结晶行为

Preparation and Crystallization of Carboxymethyl Cellulose/Silica Nanoparticle Composite

羧甲基纤维素(CMC)是纤维素中羟基被羧甲基部分取代后的产物,取代后纤维素原有的结晶结构被破坏,羧甲基纤维素为非晶态结构。采用高分子表面活性剂聚二甲基二丙烯氯化铵改性纳米二氧化硅表面,以提高其与高分子材料的相容性,使其与羧甲基纤维素复合制备结晶型羧甲基纤维素。经红外光谱(FT-IR)、扫描电子显微镜(SEM)、热重分析(TGA)分析,对复合前后的结构形态进行比较,复合物尺寸大于100nm,因此它不是纳米复合物,但发现得到了羧甲基纤维素结晶,且热性能有了提高。

Carboxymethyl cellulose（CMC） was prepared by substituting carboxymethyl group for part of hydroxyl group in cellulose. After the substitution, the crystalline structure of cellulose is broken, so CMC possesses amorphous structure. The surface of silica nanoparticles was modified by polymer surfactant poly （diallyldimethyl ammonium chloride） in order to improve the compatibility of silica with polymer material, to prepare crystalline-type CMC composite by compositing the silica and CMC with amorphous structure. The structure morphologies between CMC composite and uncomposited CMC are compared by Fourier transform infrared （FT-IR）, scanning electron microscope（SEM）, gravitational thermal analysis（TGA）. The result shows that the size of the composite is larger than 100nm, so it isn＇t a nanocomposite, but it possesses a wonderful crystalline structure, and the thermal properties are improved.