SOME ASPECTS OF POLYMERIZATION OF N-VINYLCARBAZOLE BY GRIGNARD-REAGENTS

In the reported experiments, the polymerization of N-vinylcarbazole (NVC) initiated by PhMgBr in benzene was studied at 82 degree C. R//p is second order with respect to PhMgBr concentration but increases with NVC concentration (up to 0. 06 M) and falls thereafter. R//p and P//n area depressed by the addition of thiphene and water. Modifiers such as benzaldehyde, butanone, and ethylene glycol practically inihibit the polymerization. Carbon tetrachloride and carbon dioxide, when passed through the NVC solution first, enhance the R//p and P//n to some extent. P//n increases with PhMGBr and NVC concentrations, respectively. R//p increases with temperature, but P//n shows a maximum at a certain temperature. A cationic mechanism has been proposed where the polymerization is initiated by RMg** plus cations produced from the ionization of PhMgBr by the Ashby and Smith mechanism.