College of Textiles, Donghua University, Shanghai 201620, China; MINES ParisTech, PSL Research University, CEMEF - Centre de Mise en Forme des matériaux, CNRS UMR 7635, CS 10207 rue Claude Daunesse, 06904 Sophia Antipolis Cedex, France.
College of Textiles, Donghua University, Shanghai 201620, China.
Carbohydr Polym. 2015 Jun 25;124:85-9. doi: 10.1016/j.carbpol.2015.01.065. Epub 2015 Feb 16.
The rheological properties of hydroxyethyl cellulose (HEC) with a low molar substitution (MS) dissolved in 8wt% NaOH-water were studied as a function of solution temperature, polymer concentration and molar substitution. Special attention was paid to gelation kinetics. Similar to cellulose dissolved in alkali or ionic liquids, the intrinsic viscosity of HEC decreased with temperature increase, indicating a decrease of solvent thermodynamic quality. The gelation time of HEC solutions decreased exponentially with temperature but the kinetics is much slower than the gelation of microcrystalline cellulose solutions in the same solvent. Higher molar substitution leads to slower gelation. The small amount of introduced hydroxyethyl groups prevented cellulose aggregation thus increasing solution stability.
研究了低摩尔取代度（MS）羟乙基纤维素（HEC）在 8wt%NaOH-水中的流变性，考察了溶液温度、聚合物浓度和摩尔取代度的影响。特别关注了凝胶化动力学。类似于溶解在碱或离子液体中的纤维素，HEC 的特性粘度随温度升高而降低，表明溶剂热力学质量下降。HEC 溶液的凝胶化时间随温度呈指数下降，但动力学比相同溶剂中小微晶纤维素溶液的凝胶化慢得多。较高的摩尔取代度导致凝胶化速度较慢。少量引入的羟乙基基团阻止了纤维素的聚集，从而提高了溶液的稳定性。
