A novel tertiary bromine-functionalized thermal iniferter for controlled radical polymerization

Abstract

A novel terminal tertiary bromine-containing thermal iniferter, 1,1,2,2-tetraphenylethane-1,2-diyl bis(2-bromo-2-methylpropanoate) (TPEBMP), was prepared from 1,1,2,2-tetraphenyl-1,2-ethanediol and a-bromoisobutyryl bromide. The controlled radical polymerization of methyl methacrylate and styrene was successfully carried out using TPEBMP at 70 1C. During the polymerization, the number average molecular weight increased linearly with increasing conversion. Number average molecular weight was determined by gel permeation chromatography, and was found to be similar to the theoretical molecular weight. The novel iniferter TPEBMP and the polymers prepared from this iniferter were characterized by spectral, thermal and chromatographic methods. The glass transition temperature (T g ) of the poly(methyl methacrylate) was observed at 127 1C, whereas the T g of the polystyrene was observed at 102 1C. Because the resulting polystyrene and poly(methyl methacrylate) consist of tertiary bromine at both ends of the chains, these polymers can be used as macroinitiators for atom transfer radical polymerization to synthesize tri-block copolymers.

Controlled atom transfer radical polymerization of MMA onto the surface of high-density functionalized graphene oxide

“…The linear relation between time vs. ln([M] 0 /[M]) shows that the concentration of propagating radicals is almost constant throughout the polymerization process. The small deviation in CRP results may be correlated with the induction period before starting the MMA polymerization, with similar results reported in previous literature [ 24 , 25 ]. As reported earlier, this induction period may account for the initial delay in reaching equilibrium between propagating radicals and dormant species.…”

Novel ABA block copolymers: preparation, temperature sensitivity, and drug release

“…† 1,1,2,2-Tetraphenyl-1,2-ethanediol (TPED) (where X = OH) is a well studied 1,2-disubstituted tetraphenylethane based iniferter for controlled/living radical polymerization. 20 When the OH groups are functionalized, for example, by reacting with isocyanate 12,25 or a-bromoisobutyryl bromide, it can function as an iniferter for controlled/living radical polymerization, 26 as reported in the literature.…”

“…9,10 When an iniferter is used, polymerization involves direct insertion of monomers into the iniferter bonds, resulting in two iniferter fragments at the two chain ends. Additionally, various vinyl monomers, ranging from acrylates and styrene to vinyl pyrrolidone, could be polymerized [11][12][13][14][15][16][17][18][19] under rather mild experimental conditions in the absence of metal catalysts and without multiple synthetic steps, making this method more feasible and eco-friendly, 20 compared to ATRP 20 and RAFT polymerizations. 21 While the molecular weight and polydispersity of the obtained polymers are not easily controlled compared to ATRP, RAFT, and TEMPO polymerization systems, the process is more easily adapted to practical applications.…”

Synthesis of H-shaped complex macromolecular structures by combination of atom transfer radical polymerization, photoinduced radical coupling, ring-opening polymerization, and iniferter processes

“…It was found that radicals formed from TPED do not react directly with the monomer but they form monomer radicals, which initiate the polymerization, via hydrogen transfer reaction (Scheme ). Several researches have been reported to prevent such side reactions such as reacting the OH groups of TPED with diisocyanates and α‐bromoisobutyryl bromide …”

“…Several researches have been reported to prevent such side reactions such as reacting the OH groups of TPED with diisocyanates and a-bromoisobutyryl bromide. [37][38][39][40] Since the polymers obtained by benzophenone assisted radical coupling reactions possess structurally similar tetraphenyl ethane groups at the junction point, it seemed appropriate to use them as macroiniferters. To prevent above described hydrogen transfer side reactions in the iniferter process, hydroxyl groups were first used in ringopening polymerization (ROP) by using stannous octoate, Sn(Oct) 2 .…”