Akademik Veri Yönetim Sistemi
7th European Symposium of Photopolymer Science, İstanbul, Türkiye, 19 - 22 Eylül 2022, ss.72
Photoinitiators are one of the most important components in the photochemical polymerization system. Photoinitiator systems are classified as Type I, Type II [1]. Type I photoinitiators are a type of initiator that is directly subjected to a photopolymerization process as a result of light absorption and the formation of initiator radicals that can initiate polymerization [2]. Type II photoinitiator is irradiated by light gives a bimolecular reaction with an auxiliary initiator, and the radicals are obtained [2], [3]. Photoinitiator systems are used in the preparation of polymeric films and composites [4]. Recently, the most common methods of PVA derivatization are esterification and etherification reactions, thioxantone/ benzophenone derived macrophotoinitiator systems can be synthesized by condensation and addition methods.[5], [6] In this study, one-component Type II photoinitiator Thioxanthone Catechol-O,O’-diacetic acid and Cysteine were used for esterification of polyvinyl alcohol. The effect of covalent linkage of TX group and Cysteine via esterification reaction to PVA was investigated in the terms of photoactive properties of this newly synthesized polymeric photoinitiator and the efficiency of photopolymerization reactions. UV-Vis absorption spectrum of PVA-TX-Ct confirmed the covalent attachment of TX-Ct since typical absorption at 385 nm related with Thioxanthone chromophore group was observed. Fluorescence emission spectrum was also recorded when the solutions of PVA-TX-Ct and PVA-TX-Ct-Cyst excited at 390 nm wavelength. TGA analysis were also performed. UV-Curing studies were conducted with both PVA-TX-Ct and PVA-TXCt-Cyst polymeric photoinitiators for Epoxy diacrylate curing.
References
[1] Temel, G., Aydogan, B., Arsu, N., & Yagci, Y. (2009). Synthesis and characterization of one-component polymeric photoinitiator by simultaneous double click reactions and its use in photoinduced free radical polymerization. Macromolecules, 42(16), 6098–6106. https://doi.org/10.1021/ma901162y
[2] Gruber, H.F., (1992), ‘’Photoinitiators for Free-Radical Polymerization’’, Progress in Polymer Science, 17, 953-1044.
[3] Doğruyol, Z., Karasu, F., Temel, G., Balta, D.K., Aydın, M., Keskin, S., Pekcan, Ö. ve Arsu, N., (2010), ‘’Basics and Applications of Photopolymerization Reactions’’, Chapter XI, Research Signpost, Kerala, India.
[4] Aydın, M., Arsu, N., Yagci, Y., Jockusch, S., Turro, N.J., (2005), “Mechanistic Study Of Photoinitiated Free Radical Polymerization Using Thioxanthone Thioacetic Acid As One –Component Type II Photoinitatior”, Macromolecules 38:4133.
[5] Dietliker, K. In Chemistry & Technology of UV & EB Formulation for Coatings, Inks, and Paints; SITATechnology Ltd.: London, 1991; Vol. III, pp 76-78. [6] Gacal, N.B., Koz, B., Gacal, B., Kiskan, B., Erdogan, M., Yağcı, Y., “Pyrene Functional Poly(vinyl alcohol) by “Click” Chemistry”, Journal of Polymer Science, vol. 47, no. 5, pp. 1317-1326, March 2009.
Keywords: Photoinitiators, Polymers, Crosslink Structures, Thioxanthones, Polyvinyl Alcohol, Esterification