Methacrylamide‐initiated graft copolymerisation of segmented polyurethanes

Methacrylamide, which had been stored over weeks after purification polymerized spontaneously in N,N‐dimethylformamide when left standing in sealed degassed glass ampoules for several days at room temperature. However, freshly purified methacrylamide did not polymerize under identical conditions. A free radical mechanism was postulated to account for these observations. Using the self‐initiated polymerisation of methacrylamide as free‐radical sources, poly(urethane‐g‐methacrylamide)s were synthesized. Some of the resulting graft copolymers were partially soluble in certain common organic solvents. The properties of the unmodified and graft copolymers were investigated. The graft copolymers were relatively more thermally stable than the original polyurethanes.