卤素阴离子对纤维素/NMMO/H2O体系的影响

摘要

研究了不同卤素阴离子对纤维素/N–甲基吗啉–N–氧化物(NMMO)/H2O体系稳态流变性能、动态流变性能以及再生纤维素聚合度的影响。实验结果表明：在阴离子物质的量浓度相同时，随着离子半径的增大，体系的非牛顿指数n、临界剪切速率γcr减小，体系的黏度系数K、零切黏度η0、结构黏度指数Δη增大；储能模量G′和损耗模量G"交点向低频区移动，体系中纤维素的相对分子质量变大、相对分子质量分布变宽；Cl-导致再生纤维素的聚合度下降，而 Br-、I-抑制纤维素降解作用明显。%In this research,the effects of different halogen anions on the steady-state rheological properties,dynamic-state rheological properties of the cellulose/N-Methylmorpholine-N-oxide(NMMO)/H2O system and the degree of polymeriza-tion(DP)were investigated.The results showed that the non-Newtonian exponentn and the critical shear rateγcr decreased with the increase of the ionic radius at the same amount-of-substance concentration of the anions,while the power law coef-ficientK,the zero shear viscosityη0 and the structural viscosity index Δη of the solutions increased.The cross point of stor-age modulusG′ and loss modulusG" shifted to the zone of low frequency,and the relative molecular weight and the distribu-tion of cellulose in the system increased with the increase of the ionic radius.Moreover,Cl-decreased the DP of the regener-ated cellulose,while Br-and I-inhibited the degradation of cellulose dramatically.