Reworkable Photocrosslinking System Using Multifunctional Epoxides and Photobase Generators

Quaternary ammonium salts of phenylglyoxylic acid as photobase generators for thiol-promoted epoxide photopolymerization

“…[13][14][15] Since the first report of a PBG in 1987, 16 many different photochemical base-generating systems have been documented, such as carbamates, O-acyloximes, aminimides, or ammonium salts. 14 PBG photocatalyst systems that crosslink or modify polymers can be used for the photocuring of epoxy resins, [17][18][19] in base-catalyzed Michael reactions, 20 as catalysts for imidization reactions, 21 polythiourethane formation 22 or sol-gel hydrolysis-condensation processes. 23 There are many suitable applications for PBGs in the photoresist industry.…”

A class of azocarbazole‐based carboxylates: High‐efficiency ionic unimolecular photobase generators for thiol‐epoxy click polymerization under blue light

“…Then, the desired PBGs were obtained by neutralizing the carboxylic acid with the strong bases (TBD and TMG). Their structures of Ac-C-TBD and Ac-C-TMG have been confirmed by 1 H NMR, 13 C NMR, and HR-MS (Supporting Information S1).…”

“…Hydrochloric acid, acetonitrile, methanol, diethyl ether and other solvents were purchased from Sinopharm Chemical Reagent Co. All chemical reagents were used as received without further purification. 1 H (400 MHz) and 13 C (101 MHz) NMR spectra were determined at room temperature on a VARIAN Mercury 400 spectrometer of the Spectropole. Mass spectroscopy was performed by high resolution mass spectrometer (Thermo Scientic, Waltham, MA) in the electrospray ionization (ESI) mode.…”

“…Cameron and Frechet first proposed the concept of organic carbamate PBG. 10 Since then, a series of PBGs such as carbamates, [11][12][13][14][15][16][17][18][19][20] oxime-urethanes, 12,13,21 and salts [22][23][24] have been developed. However, the most reported PBGs are only able to release relative weak amines, which are inefficient in the activation of anionic polymerization and often require postbaking.…”

Terarylenes as Photoactivatable Hydride Donors

“…The few nucleophilic photogenerators that have been reported exploit photoinduced homolytic bond cleavage pathways, leading to intermediates that undergo reactions with surrounding media to produce the desired photoproducts . Both ionic and nonionic examples including carbamates, , O -acyloximes, , and ammonium salts , have been exploited in the production of photobases as well as decarboxylation systems …”