FTIR studies on the effect of concentration of polyethylene glycol on polimerization of Shellac

© Published under licence by IOP Publishing Ltd. In the present paper, it was reported the FTIR studies on the efect of polyethylene glycol on polimerization of shellac. The shellac was shellac waxfree, and the solvent was ethanol 96%. The shellac films were were prepared by solvent- evaporation method. The concentrations of polyethylene glycol having molecular weight of 400 were 10, 30, 60, and 90 w/w %. Three peak intensity bands of C= O stretching of ester at 1709 cm-1, O-H stretching of hydroxyl group at 3400 cm-1, and C-H stretching vibration at 2942 cm-1 were observed and related to polimerization of shellac. It was found that polymerization of shellac was slowed down by polyethyelene glycol, and the degree of polymerization of shellac decreased with increasing the concentration of polyethyelene glycol.