【作者】 张毅；

【导师】 张立武；

【作者基本信息】 重庆大学 ， 高分子化学与物理， 2008， 硕士

【摘要】 淀粉胶粘剂原料来源广泛,生物可降解,是一种对环境友好的工业产品,本应具备很好的发展前景,然而却因耐水性差,干燥速度慢,流动性小等缺点,使其应用受到限制。为改善上述问题,本论文以马铃薯淀粉为原料,双氧水为氧化剂,聚乙烯醇(PVA)为二次改性剂,对可降解淀粉水基胶粘剂进行了深入的改性研究,整个过程分为两个部分:第一部分综合考虑淀粉乳浓度、氧化剂用量、反应温度、反应时间和pH值等影响因素,按L25(56)正交实验表分别在低氧化条件和高氧化条件下制备两组氧化淀粉,并配成胶粘剂,测定了粘度、失水率和耐水性,然后探讨了各正交因素对它们的影响规律,进而筛选出在两种氧化水平下分别使胶粘剂粘度适中,耐水性和失水率较优的六种氧化马铃薯淀粉。第二部分使用PVA分别对选出的氧化马铃薯淀粉进行改性,讨论了实验结果,并对相关规律进行了总结。改性研究的结果显示,由于氧化条件的不同,各正交因素对两组氧化马铃薯淀粉胶粘剂的相应性能表现出了不同的影响规律。在其它条件相同的情况下,高氧化水平淀粉强烈降解,固含量较低,使得到的氧化淀粉胶粘剂失水率和耐水性不如低氧化水平的好。然而也正是由于高氧化水平淀粉的氧化程度高,使淀粉分子的极性和分子间的相互作用增强,其与PVA进行二次改性后,得到的混合胶粘剂能表现出更好的稳定性,性能提升更明显。由此说明,高氧化程度马铃薯淀粉更适合用于本论文的研究,且其改性产品已达到了改善原淀粉胶粘剂相应缺点的目的。更多还原

【Abstract】 Starch adhesive, for its abundant resources and biodegradable property, is an environmental friendly industrial product that could be used in many fields. However, its application is limited by its bad water-resistance, slow drying speed and low fluidity. In order to improve these disadvantages of starch adhesive, this paper had studied on the modification of degradable starch water-based adhesive, which used potato starch as the raw material, H2O2 as the oxidant and PVA as the second modifying agent. The process could be separated into two parts: In the first part, taking into account influences of starch content, oxidant amount, temperature, reaction time and the pH value, starches were oxidized by L25(56) orthogonal experiments in low oxidation condition and high oxidation condition, respectively. And then, oxidized starch adhesives were prepared and the viscosity, water-loss ratio and water-resistance were tested. After that, the influencing factors on the properties of adhesives were discussed and optimized synthesis conditions for better viscosity, water-loss ratio and water-resistance of oxidized potato starches in both oxidation conditions were obtained. In the second part, the selected oxidized potato starches were modified by PVA and the results were discussed. After then, the relevant laws were summarized.The results of modification indicated that the orthogonal factors on the properties of oxidized potato starch adhesives showed different laws because of the different oxidation conditions. While the other conditions were the same, the solids content of starches in high oxidation degree, for their fierce degradable, were too low to get the water-resistance and water-loss ratio of the obtained oxidation starch adhesives worse than that obtained in low oxidation degree. However, due to their high oxidation degree, the polarity of starch molecules and the interaction between molecules were enhanced. When they were modified by PVA, the adhesives showed better stability and the properties were improved obviously. Thus potato starches in high oxidation degree were more suitable for the study of this paper and their modified products had achieved the purpose of improving the disadvantages of raw starch adhesives.更多还原