【作者】 张甄；

【导师】 梁兴泉；

【作者基本信息】 广西大学 ， 有机化学， 2008， 硕士

【摘要】 本文以广西两大优势资源蒙脱土和木薯淀粉作为原料,经蒙脱土钠化改型和淀粉马来酸酐酯化后,再与丙烯酸接枝共聚,合成新型的、可被生物降解的蒙脱土复合吸水材料。在此基础之上,测定了复合材料的吸水倍率,初探了复合材料在淀粉凝胶中的应用。对蒙脱土钠化的研究表明:最优钠化改型条件为:反应温度75℃,反应时间6 h,钠化试剂用量6%,钠化体系pH值为10.0,在此反应条件下得到的钠基蒙脱土CEC为103.31 mmol/100 g,膨胀体积达到88.3 mL/g。通过微波预处理可在一定程度上提高原土的CEC,缩短钠化精制的时间。在钠化中使用超声波振荡可让蒙脱土具有更优的抗凝沉性。对合成马来酸酐淀粉酯的研究表明:微波下马来酸酐淀粉酯最优的合成条件为:淀粉用量5.00 g,马来酸酐用量比例为0.4,吡啶用量比例为0.3,反应时间5 min,反应温度为100℃。在此条件下可以快速得到取代度为0.189的淀粉酯。对蒙脱土复合吸水材料的制备研究表明:反应温度60℃、反应时间5 h,交联剂用量为0.02%,引发剂用量为0.047%,蒙脱土用量为13.5%、马来酸酐淀粉酯用量为13.6%、丙烯酸中和度为80%时,可获得吸水倍率为746g/g的蒙脱土-淀粉酯-丙烯酸吸水复合材料。此外,本文还探讨了复合材料的吸水和保水机理。对复合材料在淀粉凝胶中的研究表明:蒙脱土-淀粉酯-丙烯酸复合材料可以与木薯淀粉形成均匀的凝胶。在木薯淀粉中加入质量分数为40%的复合材料不仅能够提高凝胶的压缩强度,而且还能缓解淀粉因失去水分而变得干硬的问题,利于拓宽淀粉凝胶的使用范围。更多还原

【Abstract】 Montmorillonite and tapioca starch are abundant in Guang Xi province,for fully utilizing these two resources,montmorillonite composite materials were synthesized in this paper.Synthesis involved the following mainly:sodium modification of montmorillonite, esterifing tapioca starch with maleic anhydride,and grafting starch maleat ester with crylic acid.Furthermore,water absorption of composite material was measured.As additive of starch gels,the application of the composite material was also explored.The results of sodium modification of montmorillonite showed that the best conditions of turning Ca-montmorillonite into Na-montmorillonite were as following:the reaction temperature was 75℃,the reaction time was 6h,the dosage of sodium reagent was 6%,and the pH was 10.0.Under optimal conditions,the CEC of Na-montmorillonite was 103.31 mmol/100 g,at he same time,the expanded volume of Na-montmorillonite was 88.3 mL/g. The CEC of the preprocessing montmorillonite with microwave increased obviously.When ultrasonic were used in sodium modification of montmorillonite,the anti-precipitability of Na-montmorillonite was improved greatly.The results of the study on the synthesis of starch maleat ester with microwave showed that the optimal reaction conditions of synthesizing were as following:the weight of tapioca starch was 5.00 g,the molar ratio to starch of maleic anhydride was 0.45,the dosage of pyridine was 0.3,the reaction temperature was 100℃,and the reaction time was 5 min. Under these conditions,the substituent degree of ester was 0.189.The results of the study on the preparation of the composite showed that the best preparation condition was the following:the amount of crosslinking reagent was 0.02%,the amount of initiation was 0.047%,the amount of montmorillonite was 13.5%,the amount of starch maleat ester was 13.6%,and the neutralization degree of cryli1 acid was 80%, temperature was 60℃,reaction time was 5h.Under this condition,the composite material could absorb distill water as high as 746 g/g.Composite and starch could be able to form uniform gels.The experiment results showed that addition of composite material could improve the compressive strength of starch gels. Water retention property of composite could delay the hardening of starch gels since the losing of water.更多还原