Introduction of 3-Hydroxypropionate Moieties to Polystyrene by Graft Through Strategy

Abstract

3-hydroxypropionate moieties grafted polystyrene [poly(S-g-3HP)] was prepared by sequentially applying the hydrogen-transfer polymerization (HTP) and the free-radical polymerization (FRP) via grafting through strategy. For this purpose, oligomeric poly(3-hydroxypropionate) with vinyl end-group (P3HP) was prepared via HTP of acrylic acid in the presence of tNaBuO as an alkaline catalyst. Then, the oligomeric P3HP was used as a comonomer in the FRP of styrene yielding the poly(S-g-3HP) copolymer, namely chemically modified polystyrene. H-1-NMR, FTIR, DSC, TGA, GPC, and MALDI MS techniques were applied to confirm the structures of both the oligomer and modified polystyrene. Glass transition temperatures of the modified polystyrene samples were found to be decreased from 103 to 84 degrees C depending upon the amount of 3-hydroxypropionate (3HP) moieties. Solution-cast films were prepared by the polystyrene homopolymer and modified polystyrenes. The contact angle values were determined to decrease gradually from 87.5 to 53.7 degrees with increasing the amount of the 3HP moiety grafted polystyrene.