PROPERTIES OF POLYURETHANE POLY(METHYL METHACRYLATE) GRAFT-COPOLYMERS

An unsaturated polyurethane macromonomer was synthesized by the step growth polymerization of poly(tetramethylene ether glycol), butane-1,4-diol, glyceryl monomethacrylate and diphenyl methane diisocyanate. Graft copolymers were prepared from this macromonomer by copolymerization with methyl methacrylate in dimethyl formamide solution at 80-degrees-C, using various concentrations of 2,2'-azobisisobutyronitrile as radical initiator. For some reaction mixtures, the graft copolymers were isolated by preparative gel permeation chromatography. The properties of samples of the polymeric reaction mixtures and isolated graft copolymers were examined by differential scanning calorimetry, stress-strain, impact and rheological tests and by scanning electron microscopy. Samples of the mixed polymer and isolated graft copolymers showed little evidence of phase separation in solution or the solid state.