Synthesis and Characterization of Water Soluble Thioxanthone - disulfide Derivative

Güçtaş A., Dizman H. M., Sarıyıldız E. E., Arsu N.

7th European Symposium of Photopolymer Science, İstanbul, Turkey, 19 - 22 September 2022, pp.77

  • Publication Type: Conference Paper / Full Text
  • City: İstanbul
  • Country: Turkey
  • Page Numbers: pp.77
  • Yıldız Technical University Affiliated: Yes


The development of new procedures aimed at reducing the environmental impact of polymerization processes has become a crucial issue. The creation of ecologically friendly coatings or prints has been one of the most significant drivers in the coatings business as consumers become increasingly concerned with environmental legislation [1]. Accordingly, synthesis of water-soluble photoinitiators is the most efficient way because using water as a non-toxic, green, and inexpensive solvent can solve many problems with classical organic compounds [2]. Some photoinitiators are suitable for photopolymerizations carried out in aqueous systems due to being converted into water-soluble by the ionic groups attached to their structure [3]. The thioxanthone molecule, besides being an excellent example of Type II photoinitiators, is also one of the first to come to mind among water-soluble photoinitiators [4]. In this study, a novel water soluble thioxanthone – disulfide derivative [O⁻Na⁺-TX-S]₂ as visible light photoinitiator was synthesized. Photophysical and photochemical characterization of water-soluble photoinitiator were investigated and then two different formulations containing [O⁻Na⁺-TX-S]₂ as photoinitiator were prepared with PEGDA/PEGMEA, and HEA/acrylamide as oligomers and thin films were obtained by curing of these formulations. Hydrogel features of the coating containing HEA/acrylamide as monomer and [O⁻Na⁺-TX-S]₂ as photoinitiator, in terms of its water-absorbent property and swelling degree were investigated. Heat flow, the polymerization rate, and monomer conversion values were found from Photo – DSC studies for the formulation containing PEGMEA/PEGDA and [O⁻Na⁺-TX-S]₂ photoinitiator.

This study was funded by The Scientific and Technological Research Council of Turkey (TÜBİTAK) with the project number: 1139B412101725


[1] Yagci, Y., Jockusch, S., & Turro, N. J. (2010). Photoinitiated polymerization: Advances, challenges, and opportunities. In Macromolecules (Vol. 43, Issue 15, pp. 6245– 6260).

[2] Benedikt, S., Wang, J., Markovic, M., Moszner, N., Dietliker, K., Ovsianikov, A., Grützmacher, H., & Liska, R. (2016). Highly efficient water-soluble visible light photoinitiators. Journal of Polymer Science, Part A: Polymer Chemistry, 54(4), 473–479.

[3] Lougnot, D. J., & Fouassier, J. P. (1988). Comparative reactivity of water soluble photoinitiators as viewed in terms of excited states processes. Journal of Polymer Science Part A: Polymer Chemistry, 26(4), 1021–1033. https://doi. org/10.1002/pola.1988.080260407

[4] Tar, H., Sevinc Esen, D., Aydin, M., Ley, C., Arsu, N., & Allonas, X. (2013). Panchromatic type II photoinitiator for free radical polymerization based on thioxanthone derivative. Macromolecules, 46(9), 3266-3272.

Keywords: Water-soluble photoinitiator, Thioxanthone, Photopolymerization, Hydrogel