Synthesis and Characterization of Superabsorbent Hydrogels Based on Natural Polymers: Kappa Carrageenan

Abstract

Abstract-This study demonstrates the synthesis of κ-carrageenan-cl-poly (DMAA) hydrogel by using N 1 N 1 Dimethyl acrylamide (DMMA) monomer, MBA as crosslinker and APS as initiator by involving free radical co-polymerization and crosslinking reaction technique at 70 °C for 4 h. The obtained κ-carrageenan-cl-poly (DMAA) hydrogel was washed and soaked in the acetone to remove the unreacted DMMA (homopolymer). The obtained hydrogel was dried at 60°C temperature to a constant weight. The infrared spectra (FTIR), X-ray diffraction analysis (XRD), Scanning electron microscopy (SEM), and the value of swelling degree of obtained κ-carrageenan-cl-poly (DMAA) hydrogel showed that κ-carrageenan was able to be crosslinked using DMAA and MBA in presence of initiator. APS concentration less than 0.05 g was not able to crosslink hydroxyls group of carrageenan. The optimised hydrogel swelling degree in water media was found to be 2740%. The κ-carrageenan-cl-poly (DMAA) hydrogel was found to be pH sensitive.