화학공학소재연구정보센터
Journal of Polymer Science Part A: Polymer Chemistry, Vol.56, No.11, 1146-1154, 2018
D-pi-a-Type Oxime Sulfonate Photoacid Generators for Cationic Polymerization under UV-Visible LED Irradiation
Four D-pi-A-type nonionic oxime sulfonate photoacid generators (PAGs) have been designed and synthesized for use in light-emitting diode (LED) excitable cationic photoinitiators, in which N, N-diphenylamino was used as electron donor with trifluoroacetophenone-based oxime sulfonates (trifluorometha-noesulfonate and p-toluenesulfonate) as electron acceptor and substituted fluorene and biphenyl groups as the p-conjugated systems. PAG-Ben-Tol (with biphenyl and p-toluenesulfonate) and PAG-Flu-Tol (with fluorene and p-toluenesulfonate) showed high quantum yields of photoacid generation (0.33-0.50) and very good thermal stability (over 250 degrees C). The absorbance spectra of these PAGs were consistent with the emission spectra of commercially gained UV-visible LED light sources. The potential of these PAGs for cationic photoinitiators was tested in two cationic monomer systems. These PAGs needed low light intensity and low concentration for photopolymerization with high conversions of monomer, for example, over 80%, gained at 3.0 mW cm(-2) from 365 to 470 nm LEDs. The photochemical mechanisms of these PAGs are comprehensively investigated and discussed in detail. (C) 2018 Wiley Periodicals, Inc.