New versatile bimolecular photoinitiating systems based on amino-m-terphenyl derivatives for cationic, free-radical and thiol–ene photopolymerization under low intensity UV-A and visible light sources

Abstract

The performance of a series of 2-amino-4,6-diphenyl-benzene-1,3-dicarbonitrile derivatives as visible light sensitizers for diphenyliodonium salt for enabling photopolymerization at different irradiation wavelengths was studied.

Thioxanthone Derivatives as a New Class of Organic Photocatalysts for Photopolymerisation Processes and the 3D Printing of Photocurable Resins under Visible Light

“…The best photoinitiating abilities (rate of polymerisation and final conversion) in ring-opening cationic photopolymerisation in the presence of bimolecular photoinitiating systems consisting in thioxanthone derivatives and TAS (0.2%/2% w/w) combinations upon exposure to LED with emission at λ max = 405 nm are exhibited by the following compounds: 2,4-diethyl-7-[4-(N-phenylanilino)phenyl]thioxanthen-9-one (T1) and 2,4-diethyl-7-(9-phenylcarbazol-3-yl)thioxanthen-9-one (T3) (FC = 59% and FC = 53% respectively). This is in agreement with the fact that these compounds are characterised by the highest values of molar extinction coefficients at λ max = 405 nm (ε T1 = 4404 [dm 3…”

“…Polymerisation initiated by visible light is considered to be an eco-friendly and sustainable alternative to traditional thermal polymerisation [1,2]. Photoinduced processes possess a lot of attractive features-mild reaction conditions, nearly no release of volatile organic compounds (VOCs), and room temperature operation with the use of convenient light sources [3]. Recently, there have been many developments in the field of photochemistry-especially in new monomers [4,5]-for monitoring on-line and/or in-situ processes of photopolymerisation [6][7][8], as well as completely new highly efficient photoinitiating systems, which are necessary for photopolymerisation processes [9][10][11].…”

Novel ketone derivative-based photoinitiating systems for free radical polymerization under mild conditions and 3D printing

“…The free radical polymerization of acrylates occupies a major part in polymer synthesis field for not only academic research, but also for industrialization applications. [16][17][18] Ketone scaffold-based chromophores are well known for their light absorption properties at the near-UV and visible range, but reports mentioning their uses for the LED activated photopolymerization are still scarce. 19,20 In this work, twelve different ketone derivatives differing by the central cyclohexanones and the peripheral substituting moieties were introduced and their photoinitiating abilities upon visible LED irradiation were investigated in detail.…”

New, highly versatile bimolecular photoinitiating systems for free-radical, cationic and thiol–ene photopolymerization processes under low light intensity UV and visible LEDs for 3D printing application

“…As such, photoinduced cationic polymerization is gaining in importance in international markets, as an easy, energy-saving and environmentally friendly method of obtaining cross-linked polymers. 26,27 Currently, versatile, highefficiency photoinitiating systems are sought out, which are useful for obtaining IPN type materials, i.e. those created through hybrid photopolymerization in one step.…”