Synthesis and free radical polymerization of N‐substituted citraconimides

N‐phenyl and N‐cyclopropylcitraconimides did not polymerize as free radicals with azobisisobutyronitrile (AIBN) as initiator. N‐allylcitraconimide, however, depending on the temperature and concentrations of the reactions, readily polymerized to produce polymers of different molecular weights. These polymers contained as much as 85% cyclic repeating units when the polymer exhibited an average molecular weight of ca. 4000. The softening point of the polymer was higher than 350°C and the compound was highly soluble in many organic solvents. The allylic CH3group in N‐substituted citraconimides and in their corresonding citraconamic acids could not be brominated with N‐bromosuccinimide.