Radiation‐induced solid‐state polymerization in binary systems. VII. Polymerization in solid–liquid equilibrium phase containing long‐chain compounds

摘要

AbstractThe radiation‐induced polymerization of binary systems consisting of vinyl monomers (mainly methyl methacrylate) and various long‐chain compounds in solid–liquid equilibrium state has been studied. Phase diagrams of these systems showed that all systems containing long‐chain compounds form a complete crystalline phase at temperatures below the solidus line. It was found that remarkable acceleration of the polymerization occurred in the solid–liquid equilibrium state. The long‐chain compounds are classified into three groups according to the acceleration effect. The group including paraffin, long‐chain esters, and cetyl alcohol exerted the largest acceleration effect over wide temperature regions at which the solid–liquid equilibrium exists. Maximum polymerization rate was observed at temperatures below the melting point in the presence of long‐chain compounds of the above‐mentioned group. It was observed in this case that the long‐chain compounds crystallized to form very fine colloidal particles and the system was soft and waxy in the solid–liquid equilibrium state. The acceleration of the polymerization in the binary system consisting of a vinyl monomer and a compound having no long‐chain substituents or in the homogeneous solution consisting of monomer and viscous solvent were far less than that in the presence of long‐chain compounds. It is suggested that the effect can be attributed to the effect of a special reaction matrix favorable to polymerization in t