Photo-living radical polymerization of methyl methacrylate by a nitroxide mediator

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

“…In fact, the formation of a significant amount of hydroxylamine lowered the yield of CMTMP in its preparation by the reaction of MTEMPO and AIBN. The molecular weight distributions of the resulting polymers were somewhat broadened as compared to those of the polymers obtained by the photopolymerization by AIBN and 4-methoxy-TEMPO in the presence of BAI [36,67]. This broad molecular weight distribution was probably due to the slow initiation by CMTMP having a low photo activity.…”

“…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.…”