【作者】 李杰；

【导师】 任皞；

【作者基本信息】 济南大学 ， 高分子化学与物理， 2010， 硕士

【摘要】 高吸水性树脂是一种结构松散的低交联密度亲水性高分子聚合物。能够吸收自身质量几百倍乃至几千倍的水分,并且吸水速度较快,保水性能较好,即使有压力的情况下也难以把水分分离出来。因此,高吸水性树脂在工业、林业、果林园艺设计和医疗卫生等领域得到非常广泛的应用。本文采用水溶液聚合法合成了高岭土复合高吸水树脂,分析测定了复合树脂的吸水性能、影响因素及其结构形貌等。在高岭土/聚丙烯酸钾复合吸水树脂的研究中,以部分中和的丙烯酸和高岭土为原料,过硫酸钾为引发剂,N,N-亚甲基双丙烯酰胺为交联剂,采用水溶液聚合法合成了高岭土/聚丙烯酸钾复合树脂。并对单体的中和度、高岭土的添加量、交联剂用量,引发剂用量和单体浓度对复合高吸水性能的影响因素进行了研究。实验结果表明:当单体的中和度为80%,引发剂用量为0.25%,交联剂用量为0.015%时,单体浓度为35%,可以合成出性能较好的复合型高吸水性树脂,其在蒸馏水与盐水中的吸水倍率分别可达728g/g和70.2 g/g。在高岭土/聚丙烯酸钾-丙烯酰胺复合吸水树脂的研究中,以部分中和的丙烯酸、丙烯酰胺和高岭土为原料,过硫酸钾为引发剂,N, N-亚甲基双丙烯酰胺为交联剂,采用水溶液聚合法合成了高岭土/聚丙烯酸钾-丙烯酰胺复合吸水树脂。实验结果表明:当丙烯酰胺用量为6%,单体的中和度为80%,引发剂用量为0.28%,交联剂用量为0.015%时,单体浓度为35%,合成的复合型高吸水性树脂在蒸馏水和盐水中的吸水倍率分别达919g/g和92 g/g。在高岭土/淀粉接枝聚丙烯酸钾复合吸水树脂的研究中,比较了玉米淀粉、木薯淀粉、土豆淀粉、地瓜淀粉、小麦淀粉分别接枝聚丙烯酸钾合成复合吸水树脂,玉米淀粉合成吸水树脂的吸水性能明显优于其它淀粉。因此以玉米淀粉、部分中和的丙烯酸和高岭土为原料,过硫酸钾为引发剂,N, N-亚甲基双丙烯酰胺为交联剂,采用水溶液聚合法合成了高岭土/淀粉接枝聚丙烯酸钾复合吸水树脂。实验数据表明,在采用玉米淀粉用量为10%的条件下,单体浓度为35%,交联剂用量为0.013%,引发剂用量0.25%,单体中和度为80%,交联共聚反应得复合吸水树脂在蒸馏水与盐水的吸水倍率分别为654g/g和66g/g。应用电子扫描显微镜(SEM)、X射线粉晶衍射(XRD)、红外光谱(IR)及热重分析(TG),对高岭土/聚丙烯酸钾高吸水树脂进行形貌分析得知,在复合过程中高岭土的结构没有发生变化,而是以微小颗粒状形态均匀分散于高分子基体中。高岭土在与反应单体复合过程中,在高分子基体发生了表面接枝聚合反应。添加高岭土的聚丙烯酸钾高吸水复合材料的热稳定性进一步提高。通过在土壤中使用上述三种复合吸水树脂实验测试表明:复合吸水树脂能有效提高土壤吸水保水能力,也能够增强土壤的抑蒸发能力和体积膨胀率,但不会影响农作物生长。更多还原

【Abstract】 Superabsorbents are loosely crosslinked hydrophilic polymers, which could absorb plenty of water in a relatively short period of time and have a better water-retention capacity under pressure. Because of their excellent features, superabsorbents are widely used in indusity, agriculture, horticulture and medicine for drug delivery and so on. A novel kaolin composite superabsorbent was prepared by water solution polymerization, its performance and influencing factors, structural characterization was also analyzed in this paper.In the study of kaolin/ poly(potassium acrylate) composite superabsorbent, using partially neutralized acrylic acid and kaolin as raw material, potassium persulfate as initiator, N,N-methylene-bis-acrylamide as crosslinking agent, this novel kaolin composite superabsorbent was prepared by water solution polymerization. The effects of amounts of neutralization degree of acrylic acid, kaolin, crosslinking agent, initiator and monomer concentration on composite superabsorbent were studied. The results showed that the high-performance composite superabsorbent could be obtained as neutralization degree of acrylic acid was 80%, weight fraction of initiator, crosslinking agent, monomer concentration was 0.25%, 0.015%, 35% respectively. The water-absorbency of the product in distilled water and saline water could be 728g/g and 70.2 g/g separately.In the experiment of kaolin/ poly(potassium acrylate-acrylamide) composite superabsorbent, using partially neutralized acrylic acid and kaolin as raw materials, potassium hydroxide as initiator, N,N-methylene-bis-acrylamide as crosslinking agent, The results showed that the high-performance composite superabsorbent could be obtained when neutralization degree of acrylic acid was 80%, weight fraction of acryamide, initiator, crosslinkingagent, monomer concentration was 6%, 0.28%, 0.015%, 35% respectively. The water-absorbency of the product in distilled water and saline water could be 919g/g and 92 g/g separately.In the test of kaolin/strach-grafting-poly(potassium acrylate) composite superabent, compared with corn starch, cassava starch, murphy starch, pachyrhizus starch crossing gafted potassium acrylate respectively, the results indicated that corn starch was the best choice. Therefore, with corn starch, partially neutralized acrylic acid and kaolin as raw material, potassium persulfate as initiator, N,N-methylene-bis -acrylamide as crosslinking agent, kaolin/strach-grafting-poly(potassium acrylate) composite superabent was prepared by water solution polymerization. The results showed:when neutralization degree of acrylic acid was 80%, wt(starch) was 10%, wt(initiator) was 0.25%, wt(crosslinking agent) was 0.013% , wt(monomer concentration) was 35%, the high-performance composite superabsorbent could be obtained. The water-absorbency of the product in distilled water and saline water could be 654g/g and 66g/g respectively.The kaolin/poly(potassium acrylate) composite superabsorbent was characterized by infrared spectroscopy(IR), X-ray diffraction(XRD), scanning electron microscopy (SEM), thermogravimetry (TG). There was no obvious change in the structure of kaolin and it was dispersed homogeneously as tiny particles in polymer, In the complexing process of kaolin and organic monomer, surface grafting polymerization took place in the polymer network. It was found that its thermal stability of superabsorbent composites was significantly enhanced by adding kaolin power.By adding composite water-absorbent resin to the soil in the experiment,the results showed it could effectively enhance the capacity of water-absorption and water-retention, improve the inhibition of evaporation capacity and volume swelling. But the growth of crops would not be affected.更多还原