| Abstract: | Initiation and propagation mechanisms of the spontaneous polymerization of the system nitroethylene–isobutyl vinyl ether were studied. An equimolar mixture of these two monomers gives white precipitates below room temperature, though they react explosively to give viscous products at higher temperature. The precipitate was found to be composed of a polynitroethylene and a cycloadduct of these two monomers. The isolated cycloadduct product is so reactive that it not only polymerizes itself spontaneously but also initiates the polymerization of nitroethylene. The polymerization of the cycloadduct was revealed to proceed without termination to produce an alternate copolymer of these two monomers. These results indicate that the explosive spontaneous polymerization of this system consists of three elementary reaction processes; (1) cycloaddition reaction between two monomers, (2) anionic polymerization of nitroethylene induced by the cycloadduct, and (3) the living ring-opening polymerization of the cyclo-adduct. |
