Stereocontrol in radical polymerization of acrylic monomers

• Published in: Macromolecular symposia. Vol. 183; no. 1; pp. 83 - 88
• Main Authors: Okamoto, Yoshio, Habaue, Shigeki, Isobe, Yutaka, Nakano, Tamaki
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.07.2002; WILEY‐VCH Verlag
• Subjects: Derivatives; Isotactic; Lewis acid; Monomers; Polymerization; Polymethyl methacrylates; Radicals; Scandium
• ISSN: 1022-1360; 1521-3900
• DOI: 10.1002/1521-3900(200207)183:1<83::AID-MASY83>3.0.CO;2-K

A clear effect of Lewis acids, such. as scandium trifluoromethanesulfonate [Sc(OTf)3], on stereocontrol during the radical polymerization of a designed monomer, benzyl α‐(methoxymethyl)acrylate was found. This Lewis acid also influenced the stereochemistry in the radical polymerization of methyl methacrylate giving a less syndiotactic and more isotactic polymer, although many Lewis acids were not effective. A catalytic amount of Lewis acids, such as Y(OTf)3 and Yb(OTf)3, also significantly enhanced isotactic‐specificity during the radical polymerization of acrylamide and its derivatives, N‐isopropylacrylamide (NIPAM) and N,N‐dimethylacrylamide. Obvious solvent and temperature effects on tacticity were observed in these polymerizations, and poly(NIPAM) with >80% triad isotactic content has been obtained in the presence of Lewis acids.