Kinetics of the γ‐radiation‐induced polymerization of methyl methacrylate in the solid state

Abstract

SynOPhStudies have been made of the y-radiation-induced polymerization of methyl methacrylate in bulk, in the solid state a t a temperature of -65°C. and a radiation intensity of 346,000 rad/hr. The reaction was found to have an extremely long induction period (-50 hr.) when pure monomer was used, and to be firsborder with respect to polymer concentration. This firsborder dependency was confirmed by a series of irradiations in which 0.6% poly(methy1 methacrylate) was dissolved in the monomer before irradiation. These irradiations showed no induction period. Nuclear magnetic resonance spectroscopy indicated a much more heterotactic polymer than that obtained in the liquid state a t -49°C.

Metal-Containing Polymers

“…They suggested that self-acceleration of the polymerization reaction was taking place, which was evidenced by the increasing yield of polymer with higher doses of radiation absorbed. A similar phenomenon was observed in the case of the polymerization of methyl methacrylate [230].…”

Stereospecific Living Radical Polymerization: Dual Control of Chain Length and Tacticity for Precision Polymer Synthesis

“…Although topochemical radical polymerization gives highly stereoregular polymers, the scope of the stereospecific polymerization of vinyl compounds is exclusively limited to 1,3-diene monomers and could not be used for common vinyl monomers. For vinyl monomers, it is difficult to prepare well-organized crystals, but it is noteworthy that solid-state polymerization of MMA gave lower syndiotactic polymers than that in solution probably due to the confinement effect …”

“…For vinyl monomers, it is difficult to prepare wellorganized crystals, but it is noteworthy that solid-state polymerization of MMA gave lower syndiotactic polymers than that in solution probably due to the confinement effect. 144…”

Initiation and Propagation Steps in the Solid State Polymerization of Vinyl Monomers

“…This monomer only leads to trace amounts of polymer when irradiated in the crystalline state (2). If, however, the monomer is subjected to very high doses of radiation, polymerization takes place after a long induction period (43). Here again the products of the radiolysis of the monomer presumably create imperfections in the crystal which favor the migration of monomer molecules towards the active sites.…”