Photo-living radical polymerization of methyl methacrylate by 2,2,6,6-tetramethylpiperidine-1-oxyl in the presence of a photo-acid generator

Selective Controlled/Living Photoradical Polymerization of Glycidyl Methacrylate, Using a Nitroxide Mediator in the Presence of a Photosensitive Triarylsulfonium Salt

“…While the photosensitive onium salts play the role of the photo-acid generator of the initiator for the cationic ring-opening photopolymerization of the oxirane monomers, it has been reported that these onium salts serve as an accelerator for the controlled/living photoradical polymerization of methacrylate monomers using 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (MTEMPO) as the mediator [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. MTEMPO has high solubility both in organic solvents and water compared with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and is a model compound of TEMPO supported on a polymer by ether linkage [25,26].…”

Controlled Photoradical Polymerization Mediated by 2,2,6,6-Tetramethylpiperidine-1-Oxyl

“…It is likely that the conversion reached its plateau at 3 h. It was found that an increase in the amount of BzCpFe II retarded the polymerization rate. BzCpFe II showed the opposite tendency against BAI and t BuS that enhanced the polymerization rate [36,37,41]. It is suggested that BzCpFe II is different from the diaryliodonium salts and triarylsulfonium salts regarding the molecular weight control mechanism.…”

“…While the nitroxides with the 2,2,5-trimethyl-4-phenyl-3-azahexane-3-oxyl skeleton provide highly controlled molecular weight distributions [25], TEMPO also has been often used as the mediator for the NMP, because TEMPO is easily available with a low cost and can be converted into a variety of derivatives that have functional groups [29,30] and are supported on polymers [31][32][33][34][35]. Recent findings that the TEMPO-mediated NMP is induced by photo irradiation involve the significance of the TEMPO mediator [36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51]. Photopolymerization has significant advantages over thermal polymerization in an energy-saving process that utilizes solar energy, local and medical applications, and photo-specific reactions.…”

“…The potential of photopolymerization has also been explored for thermal RAFT and ATRP polymerizations using photosensitive initiators [59][60][61][62] and a catalyst containing dithiocarbamate [63]. More recently, it was found that TEMPO-mediated controlled/living photoradical polymerization provided comparatively narrow molecular weight distribution (MWD) for methyl methacrylate (MMA) [36,37,41,43]. This paper describes TEMPO-mediated controlled/living photoradical polymerization, focusing MMA polymerization and the molecular design through this polymerization.…”

“…Photoradical polymerization of MMA was performed by azobis(4-methoxy-2,4-dimethylvaleronitrile) (AMDV) as the initiator and 4-methoxy-TEMPO (MTEMPO) as the mediator in the presence of bis(alkylphenyl)iodonium hexafluorophosphate (BAI) as the photo-acid generator [37]. The bulk polymerization was carried out at room temperature by irradiation with a high-pressure mercury lamp.…”