Effects of the number and position of methoxy substituents on triphenylamine-based chalcone visible-light-absorbing photoinitiators. Issue 25 (13th June 2022)

• Record Type: Journal Article
• Authors: Yen, Shih-Chieh; Lee, Zhong-Han; Ni, Jen-Shyang; Chen, Ching-Chin; Chen, Yung-Chung
• Is Part Of: Polymer chemistry. Volume 13:Issue 25(2022)
• Page Start: 3780
• Page End: 3789
• Publication Date: 2022-06-13
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/d2py00604a
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : Five visible-light-absorbing triphenylamine-based chalcone photoinitiators (CY1–CY5 ) have been synthesized for application in free radical photopolymerization. Abstract : Five visible-light-absorbing triphenylamine-based chalcone photoinitiators (CY1–CY5 ) that contain peripheral triphenylamines at both sides with various methoxy substituents of the triphenylamine moiety have been synthesized for application in free radical photopolymerization. They were confirmed through 1 H nuclear magnetic resonance (NMR), 13 C NMR, and Fourier-transform mass spectrometry results. All the compounds exhibited near-ultraviolet (UV) and visible-light absorption with a maximum absorption peak at approximately 426 nm. The photochemical reaction behavior of the compounds was investigated through photolysis, cyclic voltammetry, electron spin resonance, and theoretical calculations. Chalcone derivatives in combination with triethanolamine (TEOA) as a coinitiator were prepared and employed to initiate the free radical photopolymerization of trimethylolpropane triacrylate (TMPTA) by using a photo-DSC instrument. The CY1 -based formulation exhibited the highest final conversion efficiency under UV lamp irradiation (43%), whereas the CY4 -based formulation had the highest efficiency under 405 nm LED light irradiation (43%). In this study, the effects of the methoxy position and different-wavelength light sources were clearly investigated and discussed.