Perylene derivatives as photoinitiators in blue light sensitive cationic or radical curable films and panchromatic thiol-ene polymerizable films

Abstract

The perylene derivatives (PTCTE, BPTI and DPPDI) combined with an iodonium salt or an amine (and optionally an additive) are used as photoinitiating systems to initiate the cationic polymerization (CP) of epoxides, the free radical polymerization (FRP) of acrylates, or the thiol-ene polymerization (TEP) of a Trithiol/divinylether mixture under different irradiation sources i.e. very soft halogen lamp or laser diodes at 473nm or 457nm (blue light). Upon a blue light exposure, the PTCTE based systems are very efficient for CP and FRP and better than the camphorquinone (CQ) based reference systems. Interestingly, the combination of PTCTE with previously studied green light and red light sensitive perylene derivatives and an iodonium salt ensures the manufacture of a panchromatic thiol-ene polymerizable film (400–650nm) usable under various household LED bulbs irradiations (i.e. blue, green, yellow or red lights). The photochemical mechanisms are studied by steady state photolysis, fluorescence, cyclic voltammetry, laser flash photolysis and electron spin resonance spin-trapping techniques.