Reversible addition-fragmentation chain transfer polymerization of methacrylates containing hole- or electron-transporting groups

The controlled/living radical polymerization of 2-(N-carbazoryl)ethyl methacrylate (CzEMA) and 4-(5-(4-tert-butylphenyl-1,3,4-oxadiazol-2-yl)phenyl) methacrylate (t-Bu-OxaMA) via reversible addition-fragmentation chain transfer polymerization has been studied. Functional polymers with hole- or electron-transfer ability were synthesized with cumyl dithiobenzoate as a chain transfer agent (CTA) and AIBN as an initiator in a benzene solution. Good control of the polymerization was confirmed by the linear increase in the molecular weight (MW) with the conversion. The dependence of MW and polydispersity index (PDI) of the resulting polymers on the molar ratio of monomer to CTA, monomer concentration, and molar ratio of CTA to initiator has also been investigated. The MW and PDI of the resulting polymers were well controlled as being revealed by GPC measurements. The resulting polymers were further characterized by NMR, UV-vis spectroscopy, and cyclic voltammetry. The polymers functionalized with carbazole group or 1,3,4-oxadiazole group exhibited good thermal stability, with an onset decomposition temperature of about 305 and 323°C, respectively, as determined by thermogravimetric analysis.