Photoinduced Redox Initiation System for Delayed-Onset Radical UV-Curable Adhesives on Opaque Substrates.
- 1Department of Pure and Applied Chemistry, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba278-8510, Japan.
Abstract
Conventional radical ultraviolet (UV) curing requires optically transparent substrates owing to the rapid termination of propagating radicals, limiting its use in opaque or geometrically complex assembly cases. We report a photoinduced redox initiation system for delayed-onset radical UV-curable adhesives combining a coumarin-based photobase generator (Cou-TMG) with dilauroyl peroxide (LP). Upon UV irradiation, Cou-TMG releases 1,1,3,3-tetramethylguanidine, which reacts with LP through a redox process that continuously generates radicals, sustaining polymerization after irradiation stops. Optimized photobase generator loading and irradiation dose provide an open time sufficient for substrate lamination (low C═C conversion immediately after UV irradiation) and endow substantial postpolymerization capability (higher C═C conversion after 1 h), contrasting conventional radical UV curing systems. The delayed-onset, radical UV-curable adhesives are applicable to various multifunctional acrylates. Specifically, trimethylolpropane triacrylate-based adhesives achieve a high lap-shear strength of 4.4 MPa on aluminum, and the present system further bonds Cu, Fe, polycarbonate, and glass substrates.
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BibTeX
@article{machida2026photoinduced,
title = {{Photoinduced Redox Initiation System for Delayed-Onset Radical UV-Curable Adhesives on Opaque Substrates.}},
author = {Naoya Machida and Ataru Daimon and Daisuke Aoki and Koji Arimitsu},
journal = {ACS macro letters},
year = {2026},
month = oct,
doi = {10.1021/acsmacrolett.6c00416},
url = {https://europepmc.org/article/MED/42899733},
note = {CC BY},
}
RIS
TY - JOUR
TI - Photoinduced Redox Initiation System for Delayed-Onset Radical UV-Curable Adhesives on Opaque Substrates.
AU - Naoya Machida
AU - Ataru Daimon
AU - Daisuke Aoki
AU - Koji Arimitsu
PY - 2026
DA - 2026/10/01
JO - ACS macro letters
DO - 10.1021/acsmacrolett.6c00416
UR - https://europepmc.org/article/MED/42899733
AB - Conventional radical ultraviolet (UV) curing requires optically transparent substrates owing to the rapid termination of propagating radicals, limiting its use in opaque or geometrically complex assembly cases. We report a photoinduced redox initiation system for delayed-onset radical UV-curable adhesives combining a coumarin-based photobase generator (Cou-TMG) with dilauroyl peroxide (LP). Upon UV irradiation, Cou-TMG releases 1,1,3,3-tetramethylguanidine, which reacts with LP through a redox process that continuously generates radicals, sustaining polymerization after irradiation stops. Optimized photobase generator loading and irradiation dose provide an open time sufficient for substrate lamination (low C═C conversion immediately after UV irradiation) and endow substantial postpolymerization capability (higher C═C conversion after 1 h), contrasting conventional radical UV curing systems. The delayed-onset, radical UV-curable adhesives are applicable to various multifunctional acrylates. Specifically, trimethylolpropane triacrylate-based adhesives achieve a high lap-shear strength of 4.4 MPa on aluminum, and the present system further bonds Cu, Fe, polycarbonate, and glass substrates.
SN - 2161-1653
ER -