SYNTHESIS OF HIGH REFRACTIVE-INDEX ACRYLIC COPOLYMERS

A series of brominated carbazole-containing monomers with a polymeriza ble acrylic or methacrylic functionality were synthesized and characte rized. These monomers were polymerized thermally and characterized by differential scanning calorimetry (DSC) and refractive index via Brews ter's angle. The monomer 4-(1,3,6,8-tetrabromo-9-carbazolyl)-1-butyl a crylate (4b) was copolymerized with methyl methacrylate (M(2)) yieldin g the reactivity ratios r(1)=1.08 and r(2)=0.93; these Values were use d in the Skeist procedure to predict compositional drift with conversi on. The Alfrey-Price Q and e values for (4b) were 0.86 and 0.46, respe ctively. The copolymers were all colourless and transparent, despite t he absence of an azeotrope for this comonomer pair, and their refracti ve indices were found to lie between those of the constituent homopoly mers. Copolymers rich in methyl methacrylate (MMA) were found to be so luble, yet those rich in 4b were found to be intractable.