Bifunctional co-initiators: A new strategy for the design of efficient systems in radical photopolymerization reactions under air

• Published in: European polymer journal 2012-05, Vol.48 (5), p.956-962
• Main Authors: Ali Tehfe, Mohamad, El-Roz, Mohamad, Lalevée, Jacques, Morlet-Savary, Fabrice, Graff, Bernadette, Fouassier, Jean Pierre
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical Sciences; Exact sciences and technology; Oxygen inhibition; Photopolymerization; Physicochemistry of polymers; Polymerization; Polymers; Polymers and radiations; Radical chemistry; Silyl radical
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2012.01.022

[Display omitted] ► New co-initiators for free radical polymerization in aerated conditions are proposed. ► New bifunctional co-initiators containing amine and silane groups (silylamines). ► The amine for efficient initiation process and the silane to overcome the oxygen inhibition. ► Polymerization under visible light or very soft irradiation conditions. ► Chemical mechanisms investigated by ESR experiments. Bifunctional co-initiators containing amine and silane groups (silylamines) are proposed for radical photopolymerization in experimental conditions (e.g. low light intensity, low viscosity thin samples, UV and visible light exposure) where a strong deleterious oxygen effect occurs. In the presence of benzophenone, isopropylthioxanthone, camphorquinone, 2,6-diphenyl-4-(4′-dimethylaminophenyl) thiopyrylium tetrafluoroborate, chloro-HABI and cleavable photoinitiators, these compounds show a high reactivity under air, even better than that observed for a reference amine as a hydrogen donor. The associated mechanisms are investigated by laser flash photolysis (LFP) and Kinetic ESR.