【作者】 聂明；

【导师】 谭世语；

【作者基本信息】 重庆大学 ， 应用化学， 2004， 硕士

【摘要】 淀粉系高吸水性树脂具有原料易得、生产成本低、环境兼容性好、使用方便等优点,因而被广泛应用于众多领域。但是,由于其抗降解能力弱,重复使用效果差,使其在一些重要领域的应用受到了严重的限制。本论文根据自由基接枝聚合原理,利用淀粉与部分中和的丙烯酸接枝共聚制备高吸水性树脂。通过实验系统地研究了合成高吸水性树脂过程中淀粉类型的选择、淀粉与丙烯酸的配比、丙烯酸的中和度、引发剂的用量、反应时间、反应温度以及干燥温度等基本工艺条件,确定了最佳合成工艺,并利用红外光谱对合成的高吸水性树脂进行了表征,确定了基本结构及反应历程。同时,为提高其使用性能,对所合成的高吸水性树脂进行了高聚物的共混改性,并对共混改性物的应用性能进行了对比研究。通过对4种常用淀粉的筛选实验得出,玉米淀粉的改性效果最好;丙烯酸部分中和后的接枝效果优于直接接枝的效果。由正交实验可知,影响高吸水性树脂吸水性能的因素按由强到弱依次为丙烯酸与淀粉的配比、反应时间、反应温度、引发剂用量、丙烯酸的中和度,当淀粉与丙烯酸的配比为1:6,引发剂/原料为0.015,反应时间为2.5h,反应温度为50℃,中和度92%,干燥温度130℃时,可得到吸水率最高的接枝共聚产物,其清水吸水率达560倍,在土壤中30天的保水率达29.5%。通过对淀粉和产物的红外光谱对比分析,证实产物为淀粉与丙烯酸的接枝共聚物。对所合成的高吸水性树脂进行的共混改性研究表明,用聚乙烯醇(PVA)和聚苯乙烯(PS)与接枝共聚产物共混改性都可明显改善其抗降解性能和重复利用的性能,其中与PAV共混物的抗降解能力提高了84%,重复利用率提高51.4%;与PS共混物的抗降解能力提高了78%,重复利用率提高35.7%。而在吸水能力和保水能力上,共混物与直接产品相比有所减弱,但减弱不多。更多还原

【Abstract】 Starch superabsorbent resins have many advantages such as available raw materials, lower production cost, good environment compatibility, convenient usefulness, etc. Thus, they are widely applied in numerous fields. However, their applications in some important fields are seriously restricted because of bad anti-degradation ability and reusing property.According to the principle of the free radicals graft copolymerization, superabsorbent resins were prepared by graft copolymerizing between starch and partly neutralized acrylic acid. The technical conditions of the synthesizing process were systematically studied by experiments, which included starches selection, ratio of starch and acrylic acid, neutralized degree of acrylic acid, dosage of initiator, reacting time and temperature, and drying temperature. The optimum technical conditions were determined. By characterizing the basic structure of the product with IR spectrum, the reaction process was confirmed. In order to improve application properties of the product , the blending tests of the superabsorbent with polymers were performed. And the application properties of the blended products were contrastively studied. It was found by sieving experiments with four general starches that the corn starch had the best property for the modifying. The grafting ability of partly neutralized acrylic acid was better than that of acrylic acid. According to the result of orthogonal test, the influent factors on the water sorption of the copolymer in strength turn were the ratio of starch to acrylic acid, the reacting time, temperature, the dosage of initiator and the neutralization degree of acrylic acid. The graft copolymer had the highest water sorption at following conditions: the ratio of starch to acrylic acid was 1:6, the ratio of initiator to raw materials was 0.015:1, reacting time was 2.5h, temperature was 50℃ and neutralization degree of acrylic acid was 92%. The water sorption of the product in water was up to 560 times of itself weight. And water retention of the product had still 100 times after 30 days in soil. By contrasting analysis to the IR spectrum of the starch and graft copolymer, the product shows the IR characteristic peaks of the grafting structure, which proved that the product is the copolymer grafted by starch and acrylic acid.Blending modifications of the graft copolymer with polyvinyl alcohol (PVA) and <WP=6>polystyrene (PS) were respectively studied. The results showed that the anti-degradation ability and re-usability of the blended products were obviously improved. Compared with the graft copolymer, the anti-degradation ability of the product blended with PVA was increased by 84% and the re-usability was increased by 51.4%, and those blended with PS increased by 78% and 35.7%. However, compared to the graft copolymer, the water sorption and retention of the blending products had an acceptable drop.更多还原