Synthesis and characterization of guar gum‐graft‐polyacrylonitrile

Cerium(IV) mediated grafting of polyacrylonitrile on to guar gum was studied. Grafting parameters were studied gravimetrically, as a function of temperature, initiator concentration and Guar to acrylonitrile ratio. Higher temperatures resulted in higher monomer conversion and homopolymer formation. Both monomer conversion and extent of grafting increased with increase in cerium ion concentration in the range studied (0.91–9.12 mmol/l). Similar results were obtained with increase in monomer to guar gum ratio from 1 to 5. Grafting with this initiator was found to be generally good with high grafting efficiencies and low homopolymer formation for most experiments. The copolymers obtained were subjected to alkaline hydrolysis to convert nitrile groups in to carboxylic acid groups and the water absorbency of the resulting anionic guar gum was studied. Materials with water absorption up to 300 g/g could be obtained from this study. Copyright © 2003 John Wiley & Sons, Ltd.     

Synthesis,UV photo‐polymerization and degradation study of PEG containing polyester polyol acrylates

Succinic acid‐co‐polyethylene glycol polyester polyol acrylates, capable of in situ polymerization with UV radiation, were synthesized and characterized. Effect of structural changes such as internal branching, external crosslinking on their polymerization and degradation properties were investigated. Use of external crosslinkers reduced the polymerizability of the polymer. Lipases of different origins expedited the degradation to different extents and lipase isolated from porcine pancreas appeared to be more efficient than lipases from other sources. Copyright © 2004 John Wiley & Sons, Ltd.