VISIBLE LIGHT PHOTOPOLYMERIZATION OF METHYL METHACRYLATE COINITIATED WITH TITANOCENE AND KETOCOUMARIN DYE*

 The photosensitive system which can initiate methyl methacrylate with visible light was composedof compound 1 bis(η-5-cyclopentadienyl)-bis2,6-difluoro-3-(1-H-pyrrolyl)phenyl]titanium (titanocene) andcompound 2 (3,3'-carbonylbis(7-diethylamino coumarin)] (ketocoumarin dye). The high photosensitiveinitiating efficiency of this photosensitive system could be very promising for efficient system for laser (Ar⁺488 nm) to plate and photocuring for thick coating and ink. The variation of UV-visible spectrum of compound 2 during irradiation indicates that photolysis of compound 2 is through its triplet state and it can be quenched by O₂.The much quicker photobleaching of the photosensitive system suggests that there exists certain quick electron transfer reaction between compounds 1 and 2.