Pyrromethene derivatives as photoinitiators in free radical photopolymerization

OLGA I. TARZI, XAVIER ALLONAS, JEAN-PIERRE FOUASSIER

Brest, Telecom Bretagne, Francia

Congreso; Journées de Printemps du Groupe Français de Photochimie 2008; 2008

Groupe Français de Photochimie, Société Française de Chimie

Besides from being well known solid-state laser dyes, pyrromethenes have shown very good performance as sensitizing dyes in photopolymerization [1,2]. In this study, 1,3,5,7,8-pentamethyl pyrromethene BF2 complex (HMP, 1) and 2,6-diethyl-8-phenyl-1,3,5,7-tetramethylpyrromethene BF2 complex (EPP, 2) were used to polymerize a diacrylate in a two and a three component system, together with an amine (3) and a triazine (4). For both pyrromethenes, the highest conversion was achieved with the three component photoinitiating system. As these dyes have high fluorescence quantum yields, steady state and time resolved techniques were used to study the possible fluorescence quenching by the amine and triazine, as well as laser flash photolysis to investigate the electron transfer process that occurs in these photoinitiating systems.   [1] O. Garcia, A. Costela, I. Garcia-Moreno, R. Sastre, Macromol. Chem.  Phys. 2003,  204,  2233-2239. [2] S. Suzuki, T. Urano, K. Ito, T. Murayama, I. Hotta, S. Takahara, T. Yamaoka, J. Photopolym. Sci. and Tech. 2004,  17,  125-130.