Studies on Water Absorbency of Polyacrylamide Hydrogels

作     者：Bhadani Reena Mitra Uttam Kumar 

作者机构：Department of Chemistry Ranchi Women's College Ranchi University Ranchi-834001 India Department of Chemistry Gossner College Ranchi University Ranchi- 834001 India 

出 版 物：《材料科学与工程（中英文B版）》 (Journal of Materials Science and Engineering B)

年 卷 期：2015年第5卷第11期

页      面：399-405页

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

主　　题：聚丙烯酰胺水凝胶 吸水性能 亚甲基双丙烯酰胺 聚合物链 吸水膨胀 NaOH溶液 凝胶能力 离子强度 

摘      要：The polymerization was carried out under the different concentrations of acrylamide and crosslinker in an aqueous solution of NO2 gas as initiator at 50 oC. The resulting polyacrylamide was saponified with NaOH solution. The hydrolysed polymers show high degree of water swelling ( 500) than that of unhydrolysed polymers ( 100). Swell ability of the gel decreases with the increasing concentration of N, N- methylene bisacrylamide – a crosslinker which enhances the degree of crosslinking in the polymer chains. The increased crosslinking restricts the expansion of polymer network which causes the lowering of the water absorbency. It was observed that polymer hydration increased with the molar mass of polyacrylamide. The swell ability of polyacrylamide hydrogels is greatly lowered by the addition of ionic salts in the swelling medium. Both ionic strength and valency of the salts are responsible to decrease the water uptaking capacity of the gels which remain unaffected by nondessociating nature of urea. The hydrogels, so prepared, are stable and quite able to undergo swelling - deswelling cycles suggesting their reversible characters.