Novel polymeric photoinitiators bearing side-chain ?-aminoacetophenone moieties for ultraviolet-curable pigmented coatings

Abstract

New polymeric photoinitiators with pendant a-aminoacetophenone moieties, such as the homopolymers of 1-(4-morpholinophenyl)-2-benzyl-2- [N-methyl-N-(3-methacryloyloxypropyl)]aminopropan-1-one and of 1-(4-morpholinophenyl)-2-benzyl-2-[N-methyl-N-(3-methacryloyloxypropyl)]aminobutan-1-one have been prepared and fully characterized. Their photoinitiation activity has been also checked in the ultraviolet cure of a standard acrylic mixture, under irradiation over 380 nm, thus simulating the absorption conditions of a TiO 2 -pigmented coating formulation. The results have been compared with those found by using the corresponding low-molecularweight structural models, purposely synthesized. The activity data obtained are discussed and related to the structural requirements of the above systems.

Novel, highly efficient polymeric benzophenone photoinitiator containing coinitiator moieties for photopolymerization

“…Second, the imide group may cause chain transfer reaction in the copolymerization,26 leading to low molecular weight of the final product. Finally, the electrophilic group in the para‐position of the aromatic N‐substituted maleimide will favor the copolymerization 39. However, the phenoxyl group belongs to electron‐donating group, which will certainly go against to attain high molecular weight product.…”

Multifunctional benzoin derivatives based macrophotoinitiators: Synthesis, inorganic fillers modification, and fabrication of composite materials

“…Examples of the Norrish type I photoinitiators are polymers bearing side-chain benzoin methyl ether moieties, 20 polymeric trichloro-and α-amino-acetophenones. 21 In addition, new polymeric systems with tethered thioxanthone, anthraquinone, camphorquinone, or benzyl moieties are developed intensively as well. 19 Most popular polymeric photoinitiators of the Norrish type II are based on benzophenone, mainly because of its relatively low cost.…”

“…17,18 MPIs are defined as polymer systems containing pendant or in-chain chromophores, which after the light absorption process can generate active species capable of initiating the polymerization and crosslinking of mono-and multi-functional monomers and oligomers. 17,[19][20][21][22][23] All of the free-radical photoinitiators can be divided into two main types: (i) those capable of photofragmention (Norrish type I), and (ii) those capable of free radicals generation through hydrogen-abstraction mechanism (Norrish type II). Examples of the Norrish type I photoinitiators are polymers bearing side-chain benzoin methyl ether moieties, 20 polymeric trichloro-and α-amino-acetophenones.…”

Synthesis and Application of Macrophotoinitiators Obtained via Benzoin Tethering with Copolymers of Maleic Anhydride

“…Macrophotoinitiators are defined as polymer systems containing pendant or in-chain chromophores, which through the light absorption process can generate active species capable of initiating the polymerization and crosslinking of mono-and multi-functional monomers and oligomers [3,[7][8][9][10][11]. All of the free-radical photoinitiators can be divided into two main types: i) those capable of photofragmention (Norrish type I), and ii) those capable of generating free radicals through hydrogen-abstraction mechanism (Norrish type II).…”

“…All of the free-radical photoinitiators can be divided into two main types: i) those capable of photofragmention (Norrish type I), and ii) those capable of generating free radicals through hydrogen-abstraction mechanism (Norrish type II). Examples of the Norrish type I photoinitiators are polymers bearing side-chain benzoin methyl ether moieties [8], polymeric trichloroand α-amino-acetophenones [9]. In the last years, new polymeric systems with tethered thioxanthone, anthraquinone, camphorquinone or benzyl moieties are intensively developed [7].…”