Xanthene dyes/amine as photoinitiators of radical polymerization: A comparative and photochemical study in aqueous medium

Encinas, MV; Rufs, AM; Bertolotti, SG; Previtali, CM

Abstract

The efficiency of several xanthene dyes as photoinitiators of the free radical polymerization in aqueous medium was evaluated. These results show that dyes with triplet quantum yield higher than 0.1 present similar efficiencies, independently of their different chemical structure. A detailed study of the photophysics of the dyes under the polymerization conditions was carried out using laser time-resolved spectroscopies. These studies show that the active radicals are those which formed in the interaction of excited triplet state of the dye with the amine through an electron transfer process. In spite of this, the photoinitiation efficiency is not correlated with the triplet quantum yield. Also, the photophysics studies show that the quantum yield of the different pathways of the decomposition of the charge transfer intermediate is an important parameter to predict the efficiency of these photoinitiator systems. The experimentally measured active radical formation is well correlated with that calculated from the polymerization rate. The presence of heavy atoms in the xanthene ring increases the triplet quantum yield, but decreases the active radical yield, and then the polymerization rate. © 2009 Elsevier Ltd. All rights reserved.

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Título según WOS: Xanthene dyes/amine as photoinitiators of radical polymerization: A comparative and photochemical study in aqueous medium
Título según SCOPUS: Xanthene dyes/amine as photoinitiators of radical polymerization: A comparative and photochemical study in aqueous medium
Título de la Revista: POLYMER
Volumen: 50
Número: 13
Editorial: ELSEVIER SCI LTD
Fecha de publicación: 2009
Página de inicio: 2762
Página final: 2767
Idioma: English
URL: http://linkinghub.elsevier.com/retrieve/pii/S0032386109003267
DOI:

10.1016/j.polymer.2009.04.024

Notas: ISI, SCOPUS