PHOTO-REDOX INDUCED CATIONIC POLYMERIZATION OF DIVINYL ETHERS

The cationic polymerization of diethyleneglycoldivinyl ether was initiated by cationic species originating from the redox reaction between photochemically generated free radicals or excited state photosensitizers and various onium salts. For the oxidation of free radicals, the efficiency of the initiation process depended primarily on the redox potential of the redox couple and hence the reactivity could be altered by choosing an appropriate combination of free radical photoinitiator and onium salt. The electron transfer from excited state photosensitizers to the phenacyltetramethylenesulfonium salt showed no correlation between the free energy of the process and the initiation efficiency.