Graft copolymerization of unsaturated segmented polyurethanes with 2‐hydroxyethyl methacrylate

Relatively high molecular weight unsaturated segmented polyurethane synthesized from poly(ethylene glycol), methylene bis(4‐phenyl isocyanate), cis‐2‐butene‐1,4‐diol, and butane‐1,4‐diol was modified by graft copolymerization reaction. 2‐Hydroxyethyl methacrylate (HEMA) monomer was grafted onto the unsaturated segmented polyurethane using 2,2′‐azobisisobutyronitrile (AIBN) as initiator in N,N‐dimethylformamide (DMF) as solvent. The graft copolymers were isolated by selective solvent extraction in a Soxhlet apparatus. The effect of reaction time, initiator concentration, reaction temperature, and monomer concentration on the graft yields has been examined. The graft yields were enhanced by increased monomer concentration and reaction temperature.