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首页> 外文期刊>Journal of Applied Polymer Science >Study on physicochemical properties of thermosensitive hydrogels constructed using graft-copolymers of poly(N-isopropylacrylamide) and Guar gum
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Study on physicochemical properties of thermosensitive hydrogels constructed using graft-copolymers of poly(N-isopropylacrylamide) and Guar gum

机译：聚（N-异丙基丙烯酰胺）与瓜尔胶接枝共聚物制备的热敏水凝胶的理化性质研究

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A copolymer, poly (N-isopropylacrylamide)g-Guar gum (PNIAAm-g-GG, GPNA), was synthesized using N-isopropylacrylamide (IPAAm) and Guar gum (GG). Thermosensitive hydrogels were obtained by crosslinking GPNA with glutaraldehyde (GA). The hydrogels were pseudoplastic fluid at the temperature below lower critical solution temperature (LCST), but they were dilatant fluid at temperature above LCST. With an increase in GA, hydrogels changed from dilatant fluid to pseudoplastic fluid. The state and content of water in GPNA hydrogels were studied by differential scanning calorimetry (DSC). The results indicated the existence of freezing bound water and free water when water content of the hydrogel was more than 98.4%. The melting enthalpy of freezing bound water was higher than that of free water, but the melting temperature was lower. The content of freezing bound water was more than that of nonfreezing water. At 40 degrees C, above the LCST of hydrogel, water loss of the GPNA hydrogel was slow at the beginning, and then became more rapid with disorganization in hydrogel structure. At 35 degrees C below LCST of hydrogel, amount of water loss in hydrogels increased with square root of time. The drug was released slowly from the gel at 40 degrees C, and released more rapidly at 35 degrees C. (c) 2008 Wiley Periodicals, Inc.
机译：使用N-异丙基丙烯酰胺（IPAAm）和瓜尔胶（GG）合成了共聚物，聚（N-异丙基丙烯酰胺）g-瓜尔胶（PNIAAm-g-GG，GPNA）。通过将GPNA与戊二醛（GA）交联获得热敏性水凝胶。水凝胶在低于较低临界溶液温度（LCST）的温度下为假塑性流体，但在高于LCST的温度下为膨胀流体。随着GA的增加，水凝胶从膨胀流体变为假塑性流体。通过差示扫描量热法（DSC）研究了GPNA水凝胶中水的状态和含量。结果表明，当水凝胶含水量大于98.4％时，存在冻结结合水和游离水。冻结结合水的熔融焓高于游离水，但熔融温度较低。冻结结合水的含量高于非冻结水的含量。在高于水凝胶LCST的40摄氏度时，GPNA水凝胶的失水开始时很慢，然后随着水凝胶结构的混乱而变得更快。在水凝胶的LCST以下35摄氏度时，水凝胶中的失水量随时间的平方根增加。该药物在40摄氏度下从凝胶中缓慢释放，并在35摄氏度下更快地释放。（c）2008 Wiley Periodicals，Inc.

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