Synthesis and characterization of transparent poly ester urethane acrylate methyl methacrylate copolymers

Abstract

Poly(urethane-acrylate)s (PUAs) are a new class of polyurethane, with a wide variety of application in the field of coating, foams, elastomers, sealants, automotive and footwear industries. These materials allow high property variability and can be fitted for a specific application by changing the chemical structure of the constituents. Acrylic being the most popular component imparts excellent physical, mechanical, optical and thermal properties to PUA copolymer. The current study deals with the synthesis of hydroxyl terminated polyester (PEs) poly (1,4-butanediol ortho-phthalate) (BPE) by reacting one mol of phthalic anhydride (PA) with two mol of 1,4-butanediol (BDO) in the presence of tetrabutylorthotitanate (Ti(OBu)4) via esterification reaction. The effects of various parameters on the conversion of BPE were studied to optimize the reaction conditions. Thereafter, one mol of optimized BPE was reacted with two mol of isophorone diisocyanate (IPDI) followed by end capping with two mol of 2-hydroxyethyl methacrylate (HEMA) in the presence of dibutyltindilaurate (DBTDL) catalyst to form poly (ester-urethane acrylate) (PEUA-B) prepolymer. Finally, different composition of crosslinked PBMA/methyl methacrylate (MMA) copolymer were prepared by reacting prepolymer with MMA, in the presence of 1% azobisisobutyronitrile (AIBN) (w/w) as a chain initiator. The structural and chemical composition of BPE, PEUA-B andits copolymer were confirmed by FTIR and 1H-NMR spectroscopic methods. The compatibility of cross-linked copolymer was studied using DSC, DMA and SEM analysis. Thermal stability of pristine and copolymer was studied using TGA analysis. Specific volume analyses of all cross-linked copolymer were carried out employing Archimedes principle. This analysis indicated that newline