摘要
基于碱性水性溶剂体系采用核磁共振谱、偏光显微镜和X射线多晶衍射仪等方法研究了羟丙基纤维素的微观结构、溶解性和再生特性。实验结果表明,在较低温度下,醚化物质的量取代度为0.19、黏均分子量约2.3万道尔顿的羟丙基纤维素在8%氢氧化钠、6%尿素和6%硫脲混合水溶液中显示良好的溶解性,室温干燥和高温干燥再生后的羟丙基纤维素都为纤维素Ⅱ型晶型;在较高温度下和不良溶剂体系中,未完全溶解的羟丙基纤维素在溶液中成棒状或片状结构,且伴随着高表观黏度,室温干燥和高温干燥再生后的羟丙基纤维素均存在纤维素Ⅰ型晶型。
The microstructure, dissolution and regeneration of hydroxypropyl cellulose were investigated by NMR spectra, polarized microscope and X-ray diffraction after being dissolved in alkaline aqueous solution. The results show that, the hydroxypropyl cellulose of which the molar degree of etherification substitution is 0.19 and the viscosity average molecular weight is ca, 2.3- 104 Da is dissolved well in the solution composed of 8 % sodium hydroxide, 6% urea and 6% thiourea at lower temperatures. The cellulose II crystal was formed after being regenerated both at room temperature and above. However, the hydroxypropyl cellulose presents bar and cluster structures with high viscosities in the poor solvents and/or dissolves above 0 The cellulose I crystal was got after being regenerated both at room temperature and above.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2013年第7期93-97,共5页
Polymer Materials Science & Engineering
关键词
羟丙基纤维素
溶解性
结晶性
形态
hydroxypropyl cellulose
dissolution
crystallinity
morphology
