Lima Bean Starch-Based Hydrogels

Abstract

Hydrogels were prepared by crosslinking native lima bean starch and polyvinyl alcohol (PVA) with glutaraldehyde (GA) at varying proportions in an acidic medium. The native starch (N-LBS) and hydrogels (L-GA (low glutaraldehyde) and H-GA (high glutaraldehyde)) were examined for their water absorption capacity (WAC), swelling capacity, solubility, FTIR spectra and X-ray diffraction patterns. The hydrogels possessed higher WAC and swelling capacity than the native starch whereas an opposite trend was observed for their solubility values. The higher the GA proportion, the higher their WAC and swelling capacity, but the lower their solubility. There were indications of ether (C–O) groups and acetal rings (C–O–C) at 1023.53–1112.51 cm^-1 bands. Absorption bands of O–H groups were observed. The crystals of N-LBS, L-GA and H-GA were classified as C_B-type, C_A-type and C_B-type patterns respectively.