AbstractThe new oxazoline‐containing monomers, 4‐acrylyloxymethyl‐2,4‐dimethyl‐2‐oxazoline (AOMO), 4‐methacrylyloxymethyl‐2,4‐dimethyl‐2‐oxazoline (MAOMO), 4‐methacrylyloxymethyl‐2‐phenyl‐4‐methyl‐2‐oxazoline (PMAOMO), and the previously known monomer, 2‐isopropenyl‐4,4‐dimethyl‐2‐oxazoline (IPRO), were synthesized for addition polymerization studies. The monomers were homopolymerized in benzene using a free radical initiator and in aqueous media using emulsion techniques. Molecular weights of 8,000–15,000 (M̄w) were obtained for the homopolymers. Copolymerization studies were carried out with AOMO, MAOMO, and IPRO as M1, and methyl methacrylate (MMA), methyl acrylate (MA), styrene (STY), acrylonitrile (AN), and vinyl acetate (VA) as M2 for each case of M1. Relative reactivity ratios for the fifteen copolymers and Q and e values for the three oxazoline monomers were determined. The r1 values for AOMO and MAOMO copolymerizations indicated a lower value of k11 than expected, presumably because of steric effects. The r1 values in the IPRO copolymerizations were somewhat larger than expected. It was proposed that significant electron donation to the radical center of IPRO·by resonance effects occured.