微波辐射可促进单体或反应液快速升温,活化某些基团,对大分子链无损伤。与传统加热方法相比,微波辐射使聚合反应和产物干燥过程一步完成,可简化工艺流程,缩短反应时间,降低耗能。以淀粉、丙烯酸为主要原料,过硫酸钾为引发剂,N,N′-亚甲基双丙烯酰胺为交联剂,采用微波辐射法制备高吸水树脂。通过正交试验研究反应单体/淀粉比值、丙烯酸中和度、引发剂和交联剂的用量对高吸水树脂吸水性能的影响。得到最佳聚合反应条件为：单体/淀粉为9:1,引发剂用量0.4%,交联剂用量0.08%,中和度85%,微波低火加热5min,产品吸水倍率580.45g/g,40min吸水达到饱和。影响树脂吸蒸馏水倍率的因素由主到次为：单体/淀粉＞丙烯酸中和度＞引发剂用量＞交联剂用量,最优方案为A₂B₂C₃D₃。对最佳合成的产品进行了扫描电镜表征,并通过热重分析发现产品的热稳定性较好,产品可在较高温度下稳定使用。微波辐射法可大大缩短反应时间,简化工艺流程。

Microwave radiation could promote the monomer or reaction liquid fast, activate certain groups of macromolecule chain, and have no damage. Compared with the traditional heating method, microwave radiation is able to complete in one step by drying process, simplify technological process, shorten the reaction time, and reduce energy consumption. In this experiment, starch and acrylic acid are used as main raw materials, potassium persulfate is used as initiator, N, N′- methylene diacrylamide is used as crosslinking agent, and high water absorbent resin is prepared by microwave irradiation. The effect of reactive monomer/starch ratio, neutralization degree of acrylic acid, the amount of initiator, and cross-linking agent on the water absorbing properties are studied. The orthogonal experiment results show that the optimal reaction conditions are as follows: The ratio of monomer to starch is 9:1, initiator dosage is 0.4%, crosslinker dosage is 0.08%, and the neutralization degree of acrylic acid is 85% in microwave low-fire heating for 5min. Under such conditions, the water absorbency of the product is 569.95g/g, and getting to saturation in 40min. The effect factors of resin adsorption distillation water ratio from major to minor are monomer/starch>neutralization degree of acrylic acid＞dosage of initiator＞cross-linking agent dosage, the optimal scheme is A₂B₂C₃D₃, the optimum synthetic product is characterized by SEM, the thermal gravimetric test shows the product has the good thermal stability. Microwave radiation method is able to greatly shorten the reaction time, and simplify the process.