低取代羟乙基纤维素在碱溶剂中的溶解行为及其机制

doi:10.13475/j.fzxb.20180402906

纺织学报 ›› 2018, Vol. 39 ›› Issue (10): 22-27.doi: 10.13475/j.fzxb.20180402906

低取代羟乙基纤维素在碱溶剂中的溶解行为及其机制

收稿日期:2018-04-16 修回日期:2018-07-14 出版日期:2018-10-15 发布日期:2018-10-17
基金资助:

Dissolution behavior and mechanism of hydroxyethyl cellulose with low molar substitution in alkali solvent

Received:2018-04-16 Revised:2018-07-14 Online:2018-10-15 Published:2018-10-17

摘要/Abstract

摘要：

为改善纤维素在氢氧化钠（NaOH）水溶液中的溶解性能，通过醚化改性制备了低取代羟乙基纤维素（HEC），并借助光学显微镜、核磁共振仪、差热扫描量热仪和透射电子显微镜等研究了HEC在质量分数为8%的NaOH水溶液中的溶解行为及溶解机制。结果表明：低温下NaOH溶剂和水分子可结合形成尺寸合适、结构稳定的NaOH水合分子，与HEC大分子上的羟基键合形成HEC-NaOH-H2O缔合结构，切断了HEC大分子间氢键，HEC直接溶解；醚化改性后亲水性侧链的引入减弱了分子间作用力，增强了HEC与NaOH水合分子之间的作用强度，增强了缔合结构稳定性，促进了HEC在NaOH溶剂中的良好溶解；沿纤维长度方向HEC最外层膜溶胀成球形并逐渐破裂溶解，最终以长度为微米级、宽度为10~80 nm的微纤维形式分散在溶剂中。

关键词: 羟乙基纤维素, 低取代聚合物, 氢氧化钠, 溶解行为, 溶解机制

Abstract:

In order to improve the solubility of cellulose in NaOH solution, hydroxyethyl cellulose （HEC）with low molar substitution was prepared. The interactions between HEC (8%) and NaOH in solution were investigated by optical microscopy, nuclear magnetic resonance, dkfferential scanning calorimetry and transmission electron mecroscopy. The results show that at low temperatures (below 0 ℃) NaOH solvent combines with water molecules to form NaOH hydrates molecules with proper size and stable structure, which are bonded with hydroxy on HEC molecules to form HEC-NaOH-H₂O water association structure. HEC is gradually dissolved following with the breadage of intermolecular hydrogen bond of HKC. After etherification, the introduced hydrophilic side chains weakens the interactions between HEC molecules but strengthens interactions between HEC chains and NaOH hydrates molecules, enhancing the stability of association structure and promoting the dissolution of HEC solvent, the HEC is gradually dissolved and finally dispersed in the length of micronscale and the width around of 10-80 nm.

Key words: hydroxyethyl cellulose, polymer with low molar substitution, sodium hydroxide, dissolution behavior, dissolution mechanism

王文聪杜淑宁王鸿博高卫东. 低取代羟乙基纤维素在碱溶剂中的溶解行为及其机制[J]. 纺织学报, 2018, 39(10): 22-27.

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低取代羟乙基纤维素在碱溶剂中的溶解行为及其机制

Dissolution behavior and mechanism of hydroxyethyl cellulose with low molar substitution in alkali solvent

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