碱溶解玉米淀粉制备高吸水性树脂

Preparation of Superabsorbent Polymers by Dissolving Corn Starch with Alkali

摘要:

以玉米淀粉、丙烯酸为原料，过硫酸铵（APS）为引发剂，N,N'-亚甲基双丙烯酰胺（MBA）为交联剂，将中和丙烯酸的NaOH提前加入体系溶解淀粉，一步法制备出淀粉基高吸水性树脂（SSAP1）。通过单因素实验探究了丙烯酸与玉米淀粉质量比、丙烯酸中和度、引发剂APS用量、交联剂MBA用量对产物吸水倍率的影响，获得最优制备参数。通过FTIR、XRD、SEM分析了SSAP1微观结构，对比了SSAP1和高温糊化淀粉制备出淀粉基高吸水性树脂（SSAP）的接枝率和应用性能。结果表明，碱溶解玉米淀粉成功接枝聚丙烯酸分子链并发生交联反应形成高吸水性树脂，此方法能更有效地破坏淀粉分子内氢键并提高反应效率；SSAP1吸水速率与重复吸水性能优于SSAP；SSAP1在蒸馏水和盐水（0.1 mol/LNaCl溶液）的吸收倍率分别为464 g/g和34 g/g，相比SSAP的吸水倍率(428 g/g)和吸盐水倍率(26 g/g)有明显提升。

Abstract:

A starch-based superabsorbent polymer (SSAP1) was synthesized by one-step method using corn starch and acrylic acid as raw materials, ammonium persulfate (APS) as initiator, and N, N'-methylene-bis-acrylamide (MBA) as crosslinking agent, in which, sodium hydroxide was added into the system in advance to dissolve corn starch. The factors affecting the water absorbency of the product such as mass ratio of acrylic acid to corn starch, neutralization degree of acrylic acid, dosage of initiator and dosage of crosslinking agent were investigated by single factor experiments. The microstructure of SSAP1 was analyzed by FTIR, XRD and SEM. Besides, the graft rate and application performance of SSAP which was a starch-based superabsorbent polymer prepared by gelatinized starch at high temperature and SSAP1 were compared. The results showed that the corn starch dissolved by alkali were successfully grafted into poly(acrylic acid) chains, and the crosslinking reaction took place to form a super absorbent resin. This method can effectively destroy the internal hydrogen bond of starch molecule and improve the reaction efficiency. SSAP1 exhibited better water absorbency and repeated water absorption performance than SSAP. The absorbency of SSAP1 was 464 g/g for distilled water and 34 g/g for sodium chloride aqueous solution (0.1 mol /L), higher than the corresponding values of SSAP (428 g/g and 26 g/g).