【作者】 熊燕；

【导师】 胡志勇；

【作者基本信息】 中北大学 ， 应用化学， 2007， 硕士

【摘要】 两性离子型瓜尔胶(ZGG)是一类分子链上同时含有正负离子基团的新型水溶性瓜尔胶衍生物,具有广阔的应用前景。本文采用干法工艺制备了两性离子型瓜尔胶,同时对其溶液性质进行了初步研究,并考察了ZGG与十二烷基硫酸钠SDS组成的复配体系的表面性质。以二甲胺水溶液和氯乙酸为原料合成N,N-二甲基氨基乙酸(DMG),然后与环氧氯丙烷反应制得两性甜菜碱型中间体,即两性醚化剂2,3-环氧丙基二甲铵基乙酸盐(ECDH)。在碱条件下采用干法工艺制备了一系列不同取代度的两性离子型瓜尔胶。采用正交实验设计对合成工艺进行了优化,得到制备两性离子型瓜尔胶的较优条件是:反应时间为5h,反应温度为65℃,碱催化剂/瓜尔胶质量比是7.5×10-3,醚化剂/瓜尔胶质量比是0.625,取代度可达到0.544。对两性离子型瓜尔胶的溶液性质进行了研究,结果表明:在考察外加盐浓度范围内,ZGG的特性粘度[η]随NaCl浓度的增大不但不降低,反而升高,显示出明显的反聚电解质性质。二价金属离子对ZGG的影响大于一价金属离子对其的影响,即CaCl2>MgCl2>NaCl。对ZGG/SDS组成的复配体系进行了表面张力的测定研究,考察了它们降低表面张力效率、表面张力能力的增效作用。结果表明:ZGG/SDS复配体系具有显著的胶团化协同作用和降低表面张力的增效作用,其最大增效质量比为0.7/1。更多还原

【Abstract】 Zwitterionic guar gum(ZGG) is a group of novel water-soluble guar gum derivatives with both anionic and cationic groups, and it possesses wide application prospects. The thesis focused on the synthesis of zwitterionic guar gum by dry process, meanwhile, the viscosity behaviours of its aqueous solution were studied, furthermore the surface tension of the mixture of ZGG and sodium dodecyl sulphates(SDS) has been investigated.Dimethylamine and chloroactic acid were used as raw materials to synthesize N,N-dimethylglycine(DMG), then by the reaction of DMG with epichlorohydrin to form N-(2,3-epihydric propyl)-N-(carboxymethyl)-N,N-dimethylammonium hydroxide (ECDH). In presence of alkaline catalyst, the zwitterionic modifying agent ECDH was reacted with guargum to prepare ZGG using the dry process.The reaction condition were studied by the orthogonal experiment, and the results showed that the optimum reaction conditions were that reaction time 5h, reaction temperature 65℃, NaOH/guar gum weight ratio 7.5×10-3, and the amount of ECDH/guar gum weight ratio 0.625, under the condition, the degree of substitution of ZGG can reach 0.544.Viscosity behaviours of ZGG were studied, the results showed that it has the characteristics of typical anti-polyelectrolyte, the reduced viscosity increased as the concentration of NaCl increased, additionally, the effect of divalent metal ion was more than that of univalent metal ion: CaCl2>MgCl2>NaCl.Meantime, the surface tension of the mixture of ZGG and sodium dodecyl sulphates(SDS) were also investigated. The results suggested that ZGG had evident synergism with SDS in mixed micelle formation and surface tension reduction in binary system, and the optimum weight ratio of ZGG/SDS was 0.7/1, and the lowest surface tension can reach 28.5mN/m.更多还原