Department of Science and Engineering for Materials, Tomakomai National College of Technology, Nishikioka 443, Tomakomai 059 1275, Hokkaido, Japan.
Bruker Biospin K.K., 3-9, Moriya-cho, Kanagawa-ku, Yokohama 221 0022, Kanagawa, Japan.
Carbohydr Polym. 2015 Mar 6;117:636-643. doi: 10.1016/j.carbpol.2014.09.085. Epub 2014 Oct 7.
Nonionic gels were prepared from hydroxypropyl guar gum (HPG) with different molar substitution degrees by crosslinking with ethylene glycol diglycidyl ether (EGDE). FTIR and solid-state NMR spectroscopy revealed that the crosslinking degree of HPG gels increased with the amount of EGDE used during the reaction; this result was also confirmed by the water mobility in the swollen gels. Rheological characterization revealed behaviors typical of true gels, and their viscoelastic behaviors strongly depended on the crosslinking degree. The HPG gels absorbed buffers, aqueous saline, and water, and the absorption was not affected by the ionic strength or pH of the solution. In addition, HPG gels with high crosslinking degrees and molar substitution degrees exhibited gelation ability toward protic organic solvents such as methanol, ethanol, and 1-propanol. These HPG gels may find application as gelation agents for many industrial uses.
非离子凝胶是由不同摩尔取代度的羟丙基瓜尔胶（HPG）与乙二醇二缩水甘油醚（EGDE）交联而成。傅里叶变换红外光谱和固态核磁共振光谱表明，HPG 凝胶的交联度随反应中 EGDE 的用量增加而增加；这一结果也得到了溶胀凝胶中水流动性的证实。流变学特性分析表明其具有典型的真正凝胶行为，其粘弹性行为强烈依赖于交联度。HPG 凝胶能吸收缓冲液、盐水和水，并且吸收不受溶液离子强度或 pH 值的影响。此外，具有高交联度和高摩尔取代度的 HPG 凝胶对甲醇、乙醇和 1-丙醇等质子有机溶剂具有凝胶化能力。这些 HPG 凝胶可能作为许多工业用途的凝胶剂得到应用。
