利用壳聚糖在碱化条件下与一氯乙酸反应生成羧甲基壳聚糖

文档编号:HG311   文档字数:26501,页数:38

摘　要

 利用壳聚糖在碱化条件下与一氯乙酸反应生成羧甲基壳聚糖，并以戊二醛(GA) 为交联剂对羧甲基壳聚糖进行交联制备出水凝胶, 重点研究了羧甲基壳聚糖的制备工艺条件以及水凝胶的溶胀率、PH敏感性和各因素对羧甲基壳聚糖水凝胶溶胀性能的影响，如羧甲基壳聚糖脱乙酰度对水凝胶溶胀率的影响、交联剂的浓度对水凝胶溶胀率的影响。实验结果表明制备羧甲基壳聚糖的工艺条件：壳聚糖：氢氧化钠：一氯乙酸(质量比)为1：5：2.5，Na0H的质量百分比浓度50%，壳聚糖低温碱化处1-2小时，反应控制在45～50℃为宜; 反应时间随反应温度而不同, 一般选择4小时左右，所得产物为白色或淡黄色固体。另外羧甲基壳聚糖的脱乙酰度、交联剂用量对水凝胶溶胀率的影响较大。pH = 3.0时,水凝胶收缩,而pH = 1.0 ,5.0 ,7.4 ,9.0时,水凝胶溶胀,且在碱性条件下水凝胶的溶胀率远大于酸性条件下的溶胀率。

关键词　羧甲基壳聚糖  水凝胶   溶胀率  PH敏感性

Title  The preparation of carboxymethyl chitosan hydrogel

Abstract
      In alkaline conditions using chitosan and TCA make of carboxymethyl chitosan, and making glutaraldehyde (GA) as the crosslinker cross-link carboxymethyl chitosan for Carboxymethyl. Focusing on the conditions of chitosan and swelling of the hydrogel, PH sensitivity and various factors on swelling properties of carboxymethyl chitosan hydrogel, such as the impact of deacetylation carboxymethyl chitosan for swelling rate and the impact of crosslinker concentration for swelling rate of  hydrogel. The results show that the preparation processing conditions of carboxymethyl chitosan: chitosan: sodium hydroxide: TCA (ratio) for the 1:5:2.5. The percentage of the quality concentration of Na0H is 50%, The chitosan is treated in low temperature of alkalization for 1-2 hours,and the reaction controlled in the 45 - 50 ℃ .The reaction time varies with the temperature, generally choosing about four hours, the product is white or pale yellow solid. In addition
the deacetylation of chitosan carboxymethyl and crosslinker amount of hydrogel are important factors for swelling rate of  hydrogel.when the PH equai to 3.0, the hydrogel is shrinking, and when the pH equal to 1.0, 5.0, 7.4, 9.0 , hydrogel is swelling, and the swelling rate of gel in alkaline water conditions far greater than the ones under the acidic conditions .

Keywords   Carboxymethylchitosan  hydrogel  swelling rate  PH sensitivity

目录
一文献综述 2
1.1甲壳素 2
1.1.1甲壳素的简介 2
1.1.2甲壳素的功能 2
1.2壳聚糖 2
1.2.1壳聚糖的分子结构特征 2
1.2.2壳聚糖的理化性质 2
1.2.3壳聚糖的提取工艺 2
1.2.4壳聚糖的应用前景 2
1.2.5壳聚糖的市场现状及前景展望 2
1.3羧甲基壳聚糖 2
1.3.1羧甲基壳聚糖的分子结构与理化性质 2
1.3.2羧甲基壳聚糖的药理作用 10
1.3.3羧甲基壳聚糖的性能 2
1.3.4羧甲基壳聚糖在生物医学领域的应用 2
1.3.5羧甲基壳聚糖的应用前景 2
1.4水凝胶 2
1.4.1水凝胶简介 2
1.4.2水凝胶的制备 2
1.4.3水凝胶的性质研究 2
1.4.4水凝胶在医学领域的研究热点 2
1.4.5水凝胶在医学领域的应用 2
1.5本课题的意义和创新点 2
1.5.1选题的意义 2
1.5.2创新点 2
二  实验部分 2
2.1主要材料和仪器 2
2.1.1实验用主要材料 2
2.1.2实验用主要仪器 2
2.2 羧甲基壳聚糖的制备 2
2.2.1羧甲基壳聚糖的化学反应原理 2
2.2.2制备过程 2
2.3 羧甲基壳聚糖水凝胶的制备 2
2.3.1戊二醛交联羧甲基壳聚糖原理 2
2.3.2 实验步骤 2
2.4 水凝胶溶胀率的测定 2
2.5 羧甲基壳聚糖的脱乙酰度(DD) 对水凝胶SR 的影响 2
2.6交联剂的浓度对水凝胶SR 的影响 2
三 结果和讨论 2
3.1 羧甲基壳聚糖制备工艺的讨论 2
3.2 羧甲基壳聚糖水凝胶的性能 2
3.2.1羧甲基壳聚糖水凝胶溶胀动力学 2
3.2.2羧甲基壳聚糖水凝胶的pH敏感性 2
3.3各因素对羧甲基壳聚糖水凝胶溶胀性能的影响 2
3.3.1 羧甲基壳聚糖的脱乙酰度(DD)对水凝胶SR的影响 2
3.3.2交联剂的浓度对水凝胶SR的影响 2
四  结论 31
致    谢 32
参考文献 33

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