Relevance of linked dye-coinitiator in visible three-component photoinitiating systems: Application to red light photopolymerization

Abstract

A new visible light photoinitiating system (PIS) containing a linked dye-coinitiator dyad and a nondissociative electron donor was evaluated and compared with unlinked three components systems. Our results show that in the physical mixture of the three component PIS, addition of the nondissociative donor decreased the Rp to a great extent, whereas in combination with the dyads an increase in Rp is observed. The results were explained based on faster intramolecular electron transfer in linked pairs and point out the importance of linked initiator in three-component PIS for the first time. This system is the first example of threecomponents system with a nondissociative donor that would be useful for long life coating formulation. V C 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4325-4330

Visible light sensitive photoinitiating systems: Recent progress in cationic and radical photopolymerization reactions under soft conditions

“…), have been mentioned for red light or near-IR induced radical polymerizations [66,67,[221][222][223][224][225][226][227]. However, to the best of our knowledge, [129,213] ε623nm ∼ 28,000 M −1 cm −1 Laser diode (635 nm) Cationic photopolymerization [200] ε638nm ∼ 23,800 M −1 cm −1 LED bulb (630 nm) Cationic photopolymerization [15] ε635nm ∼ 14,400 M −1 cm −1 Laser diode (635 nm) Radical and cationic photopolymerization [150] cationic polymerization under red light (above 600 nm) has not been reported until recently (see Table 11).…”

High performance of the linked visible photoinitiator for free radical polymerization based on erythrosine B derivative

“…And these attempts include the following aspects. Light harvesting PI or PIS with excellent photoinitiator efficiencies are developed by using a suitable skeleton decorated with cleavable type I PI units or photosensitizer units of type II PIS; Photoredox catalysis from the metal complexes is used as efficient photosensitizers for the photopolymerization upon soft irradiation conditions and even in the air; One‐component PIs are synthesized by chemically incorporating the co‐initiator moiety into the photosensitizer chromophores . In this case, the initiator efficiency is enhanced and simultaneously the odor, toxicity, and migration problems from amine hydrogen donors are overcome. Novel PISs based on three‐component systems are designed to dramatically enhance the photoinitiator efficiency.…”

Shining a light on an adaptable photoinitiator: advances in photopolymerizations initiated by thioxanthones

“…Cationic photopolymerizations initiated by onium salt photoinitiators have become well-established processes in commercial applications and academic research areas. [97][98][99][100][101][102][103][104] The three-component photoinitiation systems are aimed to enhance the rate and efficiency of photopolymerization process in two simultaneously occurring reaction pathways. Photolysis of onium salts may occur through both heterolytic or homolytic bond cleavage of the photoexcited onium salt resulting in the formation of cation or radical cation species, respectively.…”