纤维素/NMMO·H_2O溶液体系流变性能的研究

Study on the Rheological Behavior of Cellulose/Monohydrate of N-methylmorpholine-N-oxide Solutions

利用 Brookfield DV-Ⅱ型粘度计对纤维素/NMMO·H2O 溶液体系的流变性能进行了研究,讨论了温度、纤维素浓度、浆粕聚合度及添加剂等对溶液粘度的影响。结果表明,纤维素/NMMO·H2O 溶液的流动活化能较低,因此其表观粘度随温度的变化不大;纤维素浓度和浆粕聚合度的增加都可使溶液粘度增大,但纤维素浓度对溶液粘度的影响更显著;抗氧化剂没食子酸丙酯(GPE)的加入减缓了加热时溶液粘度的下降,降低了纤维素的氧化降解;二甲亚砜(DMSO)的加入可有效地控制溶液粘度,改善溶液的加工性能。

The rheological properties of cellulose solution in N-methylmorpholine-N-oxide monohydrate were investigated by Brookfield DV-Ⅱ viscometer. The dependence of the shear viscosity on temperature, cellulose content, average degree of polymerization (DP) and addictives were discussed. The results showed that the cellulose solution had lower flow-activation energy, so its viscosity was less sensitive to variation of temperature. Both solutions exhibited increase in viscosity with increasing concentration and DP of cellulose. But the concentration had a significant effect on the viscosity of the solutions. As an antioxidant, GPE (gallic acid propyl ester) slowed down the decrease in viscosity of NMMO-cellulose-solution when heated and prevented oxidative degradation of cellulose. The addition of DMSO (dimethyl sulfoxide) could control the viscosity and improve the processing property of the solutions.