High-performance sunlight induced polymerization using novel push-pull dyes with high light absorption properties

Abstract

In this article, a series of three-component photoinitiating systems (PISs) based on push-pull dyes are proposed. The systems are composed of the newly synthesized push-pull dyes and different co-initiators, namely an iodonium salt and a tertiary amine (ethyl dimethylaminobenzoate EDB). Photoinitiation abilities and photochemical properties of the different investigated photoinitiating systems were studied in detail. Notably, the mechanisms related to the polymerization efficiencies were determined using different techniques such as UV-visible absorption and fluorescence spectroscopy. Moreover, the photoinitiation abilities of the threecomponent systems for the sunlight-induced polymerization processes were also 2 examined, indicating that sunlight can act as an effective light source for photopolymerization. Finally, 3D patterns with a spatial resolution were successfully produced by the direct laser writing (DLW) approach, even with photosensitive resins containing silica fillers.

Recent advances on visible light Phenothiazine-based photoinitiators of polymerization

“…Recently, investigations of dyes with structures totally disconnected from traditional photoinitiators have been carried out, providing a series of highly efficient photoinitiators activable in the visible range. Among these structures, metal organic framework (MOFs), [26][27][28] 2,3-diphenylquinoxaline derivatives, [29,30] zinc complexes, [31] camphorquinones, [32,33] chalcones, [34][35][36][37][38][39][40][41][42][43][44][45][46] chromones and flavones, [47][48][49] push-pull dyes, [50][51][52][53][54][55][56][57][58][59][60][61][62] thioxanthones, [63][64][65][66][67][68][69][70][71][72] helicenes,…”

Recent advances on visible light Triphenylamine-based photoinitiators of polymerization

“…Indeed, if the light penetration is of a few millimeters at 405 nm, this latter can reach 5 cm at 800 nm, enabling the polymerization of thick and filled polymers. With aim at developing highly efficient photoinitiating systems, a wide range of structures have been examined over the years and porphyrins, [21,22] pushpull dyes, [23][24][25][26][27][28][29][30][31][32][33][34][35][36] iodonium salts, [37][38][39][40][41][42][43] carbazoles, [44][45][46][47][48][49][50][51] phenothiazines, [52,53] cyanines, [54][55][56][57][58] zinc complexes, [59] diketopyrrolopyrroles, [60][61][62] iridium complexes, [63][64][65][66][67]…”

Recent advances on benzylidene cyclopentanones as visible light photoinitiators of polymerization

“…[1][2][3][4] With aim at reducing the environmental impact of polymerization processes through eco-responsible approaches, photopolymerization activated under low light intensity with light-emitting diodes (LEDs) or even with sunlight constitutes a promising alternative to the traditional thermal polymerization. [5][6][7][8][9][10][11][12] Compared to the traditional thermal polymerization which is carried out in solution and upon heating of the reaction medium, photopolymerization exhibits several advantages. Notably, photopolymerization can be carried out without solvents, avoiding the release of volatile organic compounds (VOC).…”

“…Among these families of dyes, dithienophospholes, [46,47] zinc complexes, [48] diketopyrrolopyrroles, [49][50][51] iridium complexes, [52][53][54][55][56][57][58][59] metal organic framework (MOFs), [60][61][62] helicenes, [63,64] benzylidene ketones, [65,66] phenothiazines, [67][68][69][70][71][72][73][74][75][76][77] camphorquinones, [78,79] curcumin, [80][81][82][83] push-pull dyes, [6,7,[84][85][86][87][88][89][90][91][92]...…”