Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Carbohydr Polym. 2018 Dec 15;202:591-599. doi: 10.1016/j.carbpol.2018.09.019. Epub 2018 Sep 15.
Cellulose nanocrystals (CNC) were carboxylated through an organic solvent free esterification method using l-malic acid (MA) to improve performance of transparent poly(methyl methacrylate) (PMMA) nanocomposites. A series of CNC carboxylated with a degree-of-substitution (DS) of 0, 0.035, and 0.20 were obtained. The presence of grafted carboxyl groups was characterized by Fourier transform infrared (FT-IR) spectroscopy and C NMR analysis, meanwhile effects of content and DS of CNC on the structure, thermal, mechanical, and optical transparency properties of the nanocomposites were assessed. The results indicated that the homogeneous dispersion of CNC and a favorable PMMA-CNC interface were necessary to enhance the properties of nanocomposites. Facilitated through hydrogen bonding interactions, the resulting films demonstrated that a low percentage loading of CNC with high DS worked as effective reinforcing agents, producing stronger and tougher films than neat PMMA films, with an improved thermal stability and retention of good transparency.
通过使用 L-苹果酸（MA）的无有机溶剂酯化法对纤维素纳米晶体（CNC）进行羧化，以改善透明聚甲基丙烯酸甲酯（PMMA）纳米复合材料的性能。获得了一系列取代度（DS）为 0、0.035 和 0.20 的 CNC 羧化物。通过傅里叶变换红外（FT-IR）光谱和 C NMR 分析表征了接枝羧基的存在，同时评估了 CNC 的含量和 DS 对纳米复合材料的结构、热性能、机械性能和光学透明性的影响。结果表明，CNC 的均匀分散和 PMMA-CNC 界面的良好相容性是增强纳米复合材料性能的必要条件。通过氢键相互作用，所得薄膜表明，高 DS 的低百分比 CNC 负载可以作为有效的增强剂，产生比纯 PMMA 薄膜更强、更坚韧的薄膜，同时具有改善的热稳定性和良好的透明度保持性。
