Syndiotactic-specific radical polymerization of N,N-dimethylacrylamide in the presence of tartrates: A proposed mechanism for the polymerization Part A Polymer chemistry

Radical polymerization of N,N-dimethylacrylamide (DMAAm) was investigated in the presence of tartrates, such as diethyl L-tartrate, diisopropyl L-tartrate, and di-n-butyl L-tartrate, in toluene at low temperatures. Syndiotactic polymers were obtained in the presence of tartrates, whereas isotactic polymers were obtained in the absence of tartrates. The syndiotactic-specificity increased with increasing amount of tartrates and with decreasing polymerization temperature. NMR analysis suggested that DMAAm and tartrates formed a 1:1 complex through double hydrogen bonding. A mechanism for the syndiotactic-specific radical polymerization of DMAAm is proposed.