Preparation of high‐molecular‐weight poly( N ‐vinylcarbazole) by the photoinduced low‐temperature solution polymerization of N ‐vinylcarbazole in 1,1,2,2‐tetrachloroethane

For the preparation of high‐molecular‐weight (HMW) poly( N ‐vinylcarbazole) (PVCZ) with a narrow molecular weight distribution, N ‐vinylcarbazole (VCZ) was solution‐polymerized in 1,1,2,2‐tetrachloroethane (TCE) at −20, 0, and 20°C with photoinitiation. The effects of the polymerization temperature and the concentrations of the polymerization solvent and photoinitiator on the polymerization behavior and molecular parameters of PVCZ were investigated. A low polymerization temperature with photoirradiation was successful in obtaining HMW PVCZ with a smaller temperature rise during polymerization than that for thermal free‐radical polymerization by azobisisobutyronitrile (AIBN). The photo‐solution‐polymerization rate of VCZ in TCE was proportional to [AIBN] 0.45 . The molecular weight was higher and the molecular weight distribution was narrower for PVCZ made at lower temperatures. For PVCZ prepared in TCE at −20°C with a photoinitiator concentration of 0.00003 mol/mol of VCZ, a weight‐average molecular weight of 920,000 was obtained, with a polydispersity index of 1.46, and the degree of transparency converged to about 99%. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2391–2396, 2003