Synthesis and characterization of poly(ethylene-vinyl alcohol)-g-poly(phenyl ethyl methacrylate) copolymers by a grafting onto method

Graft copolymers of poly(ethylene-vinyl alcohol)-g-poly(phenyl ethyl methacrylate) copolymers were prepared by a grafting onto method in two steps. In the first step carboxyl terminated poly(phenyl ethyl methacrylate) (PPHETMA) were prepared by solution radical polymerization using 4,4-azobis(cyanovaleric acid) (ACVA) as initiator and thioglycolic acid (TGA) as matched chain transfer agent and then converting carboxyl groups into acid chloride terminated prepolymer by reacting with oxalyl chloride. In the second step acid chloride terminated prepolymers were reacted to the ethylene-vinyl alcohol (EVOH) backbone. Grafting was confirmed by Size Exclusion Chromatography (SEC), Fourier Transfer Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. Thermal properties of the graft copolymers were studied by Differential Scanning Calorimetery (DSC) and Dynamic Mechanical Thermal Analysis (DMTA).