Syed Ishraque Ahmad, Nasreen Mazumdar
Department of Chemistry, Jamia Millia Islamia University, New Delhi 110025, India.
Chemical modification of polyvinylalcohol (PVA) through its hydroxyl groups open new areas of applications for this material like as a support for sustained delivery of bioactive compounds. The hydroxyl groups of PVA belonging to the same and different chains were crosslinked with dicarboxylic acids; malonic (MLA) and succinic acids (SA) to different degrees to produce water insoluble films. The crosslinked PVA films were then iodinated in iodine-ethanol solution and iodine/potassium iodide (KI) solution separately. The crosslinking reaction of PVA with different dicarboxylic acids followed by iodination reaction of crosslinked PVA films in different iodine solutions have been established by FTIR spectroscopy. The thermal properties of crosslinked PVA films before and after iodination were characterized by TGA and DSC. The swelling behaviour of crosslinked PVA films at different conditions were also studied. The crosslinked films iodinated in iodine-ethanol solution showed weight gain and turned reddish brown in colour. However, the films iodinated in iodine (I2)/KI solution were dark blue in colour. The cumulative amount of iodine released in various forms from the crosslinked PVA films iodinated with iodine-ethanol and I2/KI aqueous solutions was measured using UV-VIS spectrophotometer and titrimetric method. The results showed that crosslinked PVA films with optimum thermal and water absorbance properties could be used as iodine delivery system.