交联瓜尔胶制备工艺

以瓜尔胶为原料、环氧氯丙烷为交联剂、氢氧化钠为催化剂、乙醇为溶剂,对交联瓜尔胶的制备工艺进行研究。考察环氧氯丙烷用量、pH值、反应时间、反应温度和乙醇质量分数对交联瓜尔胶沉降积的影响。结果表明,环氧氯丙烷用量、pH值、反应时间、反应温度和乙醇质量分数对瓜尔胶交联反应均有影响。制备交联瓜尔胶的最佳工艺条件为交联剂环氧氯丙烷用量8%、pH值、反应时间3.5h、反应温度40℃、乙醇质量分数95%。瓜尔胶交联反应的影响主次顺序依次为环氧氯丙烷用量>反应温度>pH值>反应时间>乙醇质量分数。热分析表明,随着交联瓜尔胶交联度的增加,交联瓜尔胶的热稳定性、焓变、吸收峰起始温度、峰值温度和结束温度增加。

Preparation of Cross-linked Guar Gum

The preparation of cross-linked guar gum was investigated by using epichlorohydrin as the cross-linking agent,sodium hydroxide as the catalyst and ethanol as the solvent in this study.The effects of epichlorohydrin amount,pH,reaction time,reaction temperature and alcohol concentration on the sediment volume of cross-linked guar gum was explored.The results showed that epichlorohydrin amount,pH,reaction time,reaction temperature and alcohol concentration had obvious impact on cross-linked reaction of guar gum.The optimal conditions for preparing cross-linked guar gum were epichlorohydrin amount of 8%,reaction time of 3.5 h,reaction temperature of 40 ℃ and ethanol concentration of 95%.Five reaction conditions were ranked in decreasing order of their effect on the sediment volume of cross-linked guar gum as follows: epichlorohydrin amount,reaction temperature,pH,reaction time and alcohol concentration.The thermal stability,enthalpy change,endothermic onset temperature,peak temperature and final temperature of cross-linked guar gum increased with increasing degree of cross-linking.