Hybrid organic–inorganic macromolecular photoinitiator system for visible-light photopolymerization

• Published in: Progress in organic coatings Vol. 77; no. 11; pp. 1848 - 1853
• Main Authors: dell’Erba, Ignacio E., Arenas, Gustavo F., Schroeder, Walter F., Asmussen, Silvana V., Vallo, Claudia I.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2014
• Subjects: Consumption; Conversion; Decomposition reactions; Hybrid organic–inorganic; Irradiation; Jewelry; Macrophotoinitiator; Monomers; Photoinitiators; Photopolymerization; Polymerization; Sol–gel; Hybrid organic–inorganic; Macrophotoinitiator; Sol–gel; Photopolymerization
• ISSN: 0300-9440; 1873-331X
• DOI: 10.1016/j.porgcoat.2014.06.010

•Amino-functionalized macromolecular photoinitiator for visible-light was synthesized.•Hybrid organic–inorganic photoinitiator (OI-AH) was synthesized by sol–gel process.•Hydrolytic condensation of amino-functionalized silane resulted in bulky OI-AH.•The camphorquinone/OI-AH pair is very attractive for polymerization of methacrylates. Hybrid organic–inorganic macrophotoinitiator bearing pendant tertiary amine groups (OI-AH) was prepared by hydrolytic condensation of a silane containing amino groups. The macromolecular amino-functionalized photoinitiator was used in combination with camphorquinone (CQ) for visible-light photo-polymerization. The OI-AH was incorporated into methacrylate resins at loadings between 1 and 10wt.%. The photodecomposition of the CQ/OI-AH in methacrylate monomers under visible light irradiation (λ=470nm) was examined. The photolysis products of CQ/OI-AH were transparent at the irradiating wavelengths; consequently, the consumption of the CQ is accompanied by increased light intensity in the underlying lays. The clean and rapid photobleaching of CQ in combination with OI-AH makes this photoinitiator system very attractive for polymerization of thick sections. The evolution of monomer conversion versus irradiation time showed that the OI-AH is an efficient co-initiator of CQ because a fast reaction and high conversion of methacrylate groups result after 60s irradiation with a LED source of 140mW.