화학공학소재연구정보센터
Journal of Polymer Science Part A: Polymer Chemistry, Vol.52, No.9, 1334-1343, 2014
Controlled Cationic Alternating Copolymerization of Various Enol Ethers and Benzaldehyde Derivatives: Effects of Enol Ether Structures
Significant structural effects of enol ether monomers were demonstrated in cationic alternating copolymerizations with benzaldehyde derivatives (BzAs). -Methyl, -methyl, ,-dimethyl, and cyclic enol ethers were copolymerized with BzAs by the EtSO3H/GaCl3 system with 1,4-dioxane in toluene at -78 degrees C. -Methyl and cyclic monomers, -monosubstituted compounds, induced copolymerizations with BzAs, some of which were well controlled to yield alternating copolymers with controlled molecular weights (MWs) and narrow MW distributions. Conversely, an -methyl vinyl ether (VE) did not copolymerize with BzAs at all, probably due to its high reactivity and unfavorable ketal linkage formations. In addition, a ,-dimethyl VE underwent only cyclotrimerizations because of its larger steric repulsion. The product alternating copolymers, especially those with cyclic units, exhibited improved thermal properties compared to those with simple VEs units. Under appropriate conditions, the alternating copolymers selectively degraded into the corresponding cinnamaldehyde derivatives by acid hydrolysis. (c) 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1334-1343