From metal‐catalyzed radical telomerization to metal‐catalyzed radical polymerization of vinyl chloride: Toward living radical polymerization of vinyl chloride

Abstract

The metal-catalyzed radical polymerization of vinyl chloride (VC) in orthodichlorobenzene initiated with various activated halides, such as ␣,␣-dihaloalkanes, ␣,␣,␣-trihaloalkanes, perfloroalkyl halides, benzyl halides, pseudohalides, allyl halides, sulfonyl halides, ␣-haloesters, ␣-halonitriles, and imidyl halides, in the presence of Cu(0)/2,2Ј-bipyridine, Fe(0)/o-phenantroline, TiCp 2 Cl 2 , and other metal catalysts is reported. The formation of the monoadduct between the initiator and VC was achieved with all catalysts. However, propagation was observed only for metals in their zero oxidation state because they were able to reinitiate from geminal dihalo or allylic chloride structures. Poly(vinyl chloride) with molecular weights larger then the theoretical limit allowed by chain transfer to VC were obtained even at 130°C. In addition, the most elemental features of a living radical polymerization, such as a linear dependence of the molecular weight and a decrease of polydispersity with conversion, were observed for the most promising systems based on iodine-containing initiators and Cu(0), that is, IOCH 2 OPhOCH 2 OI/Cu(0)/bpy (where bpy ϭ 2,2Ј-bipyridyl), at 130°C. However, because of the formation of inactive species via chain transfer to VC and other side reactions, the observed conversions were in most cases lower than 40%. A mechanistic interpretation of the chain transfer to monomer in the presence of Cu species is proposed.

Pseudohalogens in atom transfer radical polymerization of methyl methacrylate

“…They observed that BzBr/CuSCN was more efficient for ATRP system than BzSCN/CuSCN for styrene and methyl acrylate. Asandei and Percec 19 carried out ATRP of vinyl chloride using thiocyanate and azide initiators. They observed very broad polydispersity (PDI ¼ 2.0-3.0).…”

“…Thiocyanates, isothiocyanates, and isocyanates are interesting pseudohalides which can undergo different types of chemical transformations under suitable reaction conditions. 34 There are very few reports 19,35,36 of using thiocyanate as a pseudohalide anion for the ATRP catalyst. This investigation reports the use of different pseudohalides as initiators as well as the counter anion for the metal catalyst in ATRP of methyl methacrylate (MMA).…”

“…Among all the catalysts Cu 4 and Ru 5 have been widely studied. Percec coworkers [19][20][21] used various copper catalysts having different anionic ligands other than conventional halides. They used sulfur based anionic ligands (like butanethiolate, thiophenoxide), selenide, and tellurides.…”

Aqueous SET-LRP catalyzed with “in situ” generated Cu(0) demonstrates surface mediated activation and bimolecular termination

“…3 Subsequently, SET-LRP was expanded to acrylates, [4][5][6][7][8][9][10][11][12][13][14][15][16][17] methacrylates, 8,[18][19][20][21][22][23][24][25] acrylamides, [26][27][28][29][30][31] methacrylamide, 32 acrylonitrile, 33,34 and monomers containing more complex water soluble side groups, such as sugars, 35,36 N-(2-hydroxypropyl) methacrylamide, 32 dimethylacrylamide, 26 N-isopropylacrylamide, 26,[37][38][39] oligo(ethylene oxide) methyl ether acrylate, 40 oligo(ethylene oxide) methyl ether methacrylate, 41 hydroxyethyl acrylate, 10 hydroxyethyl methacrylate 23 and acryloyl morpholine. 42 At the same time as these developments, the list of solvents used in SET-LRP was expanded to other solvents that in combination with aliphatic N-donor ligands, such as tris[(2-dimethylaminoethyl)...…”

Single electron transfer-living radical polymerization of acrylonitrile catalyzed by lanthanum powder

“…[18][19][20][21][22][23] The defective has been perfected by SET-LRP for its polymerization of nonactivated vinyl chloride. [24][25][26] From the mechanism of SET-LRP, activation of initiator and dormant halide chain ends is catalyzed by the out-sphere electron transfer (OSET). 27 Compared to the inner-sphere electron transfer (ISET) of atom transfer radical polymerization (ATRP), SET-LRP has lower activation energy.…”