Preparation of poly(vinyl alcohol) hydrogels with radiation grafted citricand succinic acid groups

Ternary mixtures of PVA/Citric acid (CA)/water and PVA/Succinic acid (SA)/w ater were gamma irradiated to various doses in air at ambient temperature. Gelation % vs dose curves were constructed and swelling behavior of gels wi th maximum conversions was studied. In maximum gelled systems 80% of CA use d in the feed composition was retained in the gel structure whereas this wa s only 20% for SA. The volume of swelling of ionic PVA gels increased from 230% to 530% for PVA/CA systems when pH was increased from 2.6 to 7.5. Less significant increase in swelling was observed for PVA/SA gels, from 250% t o 330% in the same pH interval. The incorporation of SA and CA groups onto PVA networks improved remarkably the affinity of these structures for Co2and Ni2+ ion uptake. (C) 1999 Elsevier Science Ltd. All rights reserved.