Radical photopolymerization of 2-ethyl-2-(hydroxymethyl)-1,3-propanediol triacrylate (TMPTA), photoinduced with redox system: electron donor-acceptor has been presented. Xanthene dye i.e. 5,7-diiodo-3-pentoxy-6-fluorenone (DIPF) was used as acceptor. Electron donor in the system investigated was benzenesulfinic or (phenylthio)acetic acid tetrabutylammonium salt (BSAAS or PTAAAS). Calculated from Rehm-Weller negative value of the free energy of activation of the photoinduced electron transfer (ΔGel) suggests that transfer of the electron from BSAAS to DIPF is possible and that obtained in this proces sulfonyl radicals or products of disproportionation reactions of the ones are the photoinitiating radicals. There is no correlation between the rate of the photopolymerization (Rp) of TMPTA and square root of BSAAS as on electron donor concentration. Rp is approximatelly proportional to the square root of absorbed light intensity (Ia), however some deviation from the fit at low intensity is observed.
Key words: photopolymerization, 2-ethyl-2-(hydroxymethyl)-1,3-propanediol triacrylate, redox photoinitiators, xanthene dyes
M. Pietrzak, A. Głuszak, A. Wrzyszczyński
Photopolymerization of multifunctional monomer initiated with redox system dye-sulfur compounds