Macromolecular crossover reaction of disulfide containing polymers by free radical generator or upon photoirradiation

In this study, macromolecular crossover reaction of disulfide-containing polymers was investigated. The reaction proceeded in the presence of radical generators such as benzoyl peroxide at 80°C in anisole. The fractionated polymer with narrow molecular weight distribution reorganized to the polydispersed polymer due to the chain transfer reaction, but no decomposition of repeating units was observed during the reaction. The number average molecular weight slightly decreased after the reaction because catalytic amount of free-radical generators gave terminal groups of the polymer chains. The photoinduced macromolecular crossover reaction of disulfide-containing polyester and polyurethane was successfully carried out in tetrahydrofuran to afford the corresponding scrambled polymer.