棉纤维在LiCl/DMAc极性溶液中的溶解性能研究

Research of the Solution of Cotton Cellulose in LiCl/DMAc Polar Solvent

采用不同方法将棉纤维活化并溶解在LiCl/DMAc极性溶液中,研究了活化方法、溶解温度、时间及LiCl浓度对棉纤维素溶解性的影响。结果表明:DMAc热活化法为较好的活化方法;提高溶解温度,延长溶解时间及提高LiCl浓度均有利于棉纤维溶解;棉纤维在LiCl质量分数为12%的LiCl/DMAc溶液中,150℃下搅拌4h,溶解度可达3%。碱活化法使棉纤维素聚合度大幅度降低,可提高棉纤维溶解度至8%。通过扫描电镜和X射线衍射方法研究了棉纤维在前处理和溶解过程中的形态和结构变化,初步揭示了纤维素高温处理后在低温下发生溶解的机理。

The cotton cellulose activated by different ways was dissolved in LiCl/DMAc solvent.Influences of activation ways, the dissolving temperature and time, and the concentration of LiCl on dissolving ability of cotton were investigated. The results showed that the activation by hot DMAc was better than other ways. Increasing of the dissolving temperature and time, and the concentration of LiCI was favour to dissolving the cotton cellulose. 3% mass concentration cotton cellulose could be completely dissolved when the concentration of LiCI was 12%, temperature 150℃ and stirring time 4 h. The polymerization degree of cotton cellulose activated by NaOH solution was obviously decreased, which improved the dissolving ability of cellulose. 8% mass concentration of cotton cellulose could be dissolved. The morphology and structure change of cellulose during the dissolving process were determined by SEM and XRD methods, it revealed that cellulose was dissolved at the low temperature after the treatment at the high temperature.