摘要
纤维素中含有大量的氢键和致密的结晶结构使其难溶解于大多数普通溶剂,经醚化处理后的低取代度羟乙基纤维素(HEC)低温下可以溶解在NaOH溶剂中,但NaOH浓度对HEC溶解行为及溶解机制的影响尚未清晰。文中通过偏光显微镜观察HEC处于不同浓度NaOH水溶液中的溶解行为,通过差示扫描量热仪研究了HEC与不同浓度NaOH溶剂的相互作用。研究发现HEC可溶解在4%~14%的NaOH水溶液中,不同浓度NaOH水溶液可溶解的HEC最大固含量与溶液中N_(NaOH/HEC)的值有关,当其达到N值以上时,HEC可完全溶解;在8%~12%NaOH溶液中,NaOH与水分子可结合形成适当大小且相对稳定的NaOH水化物进入HEC大分子内部,从而切断HEC分子链间的氢键使HEC直接溶解,而超过此浓度范围的NaOH溶液形成的水化物尺寸不利于HEC溶解。
The large amount of hydrogen bonds and dense crystal structure of hydroxyethyl cellulose(HEC)make it difficult to dissolve in most solvents.However,etherified low-substituted HEC can be dissolved in NaOH solvent at low temperature.The effect of NaOH concentration on HEC dissolution behavior and dissolution mechanism is not clear.In this paper,the dissolution behavior of HEC in different concentrations of NaOH solution was observed by polarized light microscopy(POM),and the interaction between HEC and NaOH solvent with different concentrations was studied by differential scanning calorimetry(DSC).It is found that HEC can be dissolved in NaOH solution with concentrations of 4%~14%,and the maximum solid content of HEC soluble in different NaOH aqueous solutions is related to the value of NNaOH/HEC in solution.When it reaches above N value,HEC can be completely dissolved;in 8%~12%NaOH solvent,NaOH hydrates composed of NaOH and water molecules have proper size and stable structure,which connect with HEC macromolecules to cut off hydrogen bonds between HEC molecular chains,leading to the direct dissolution of HEC.The size of the hydrates formed in the NaOH solutions beyond this concentration range is not conducive to HEC dissolution.
作者
杜淑宁
王文聪
王鸿博
Shuning Du;Wencong Wang;Hongbo Wang(Jiangsu Engineering Technology Research Center of Functional Textiles,Jiangnan University;Key Laboratory of Eco-Textiles,Ministry of Education,Jiangnan University,Wuxi 214122,China)
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2020年第10期120-126,共7页
Polymer Materials Science & Engineering
基金
国家自然科学基金资助项目(51703085)
江苏省自然科学基金资助项目(BK20170189)
中国博士后科学基金项目2019M651574
江苏省博士后科研资助计划(2018K108C)
江苏省产学研合作项目(BY2018039)。
关键词
低取代度
NAOH溶液
羟乙基纤维素
溶解行为
low substituted degree
NaOH solution
hydroxyethyl cellulose
dissolution behavior
