Controlled radical polymerization by carboxyl‐ and hydroxyl‐terminated dithiocarbamates and xanthates

Abstract

Carboxyl-and hydroxyl-terminated dithiocarbamates and xanthates were practically synthesized. Carboxyl-and hydroxyl-terminated polymers were made from them. These reversible addition-fragmentation chain transfer (RAFT) agents had low chain-transfer constants that resulted in wider molecular distributions for the polymers. Nevertheless, kinetic studies showed that the polymerization behaved like a RAFT-mediated process after a fast start. 1 H NMR and matrix-assisted laser desorption/ionization spectra confirmed that the functional group or groups were cleanly transferred to the polymer end or ends. The copolymerization of methacrylates and acrylates could bring the former under control during radical polymerization. Block copolymers were synthesized through the condensation of the functional polymers with other types of functional polymers or through the condensation of the functional agents followed by radical polymerization. V V C 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: [4298][4299][4300][4301][4302][4303][4304][4305][4306][4307][4308][4309][4310][4311][4312][4313][4314][4315][4316] 2006

Macromolecular Design by Interchange of Xanthates: Background, Design, Scope and Applications

“…Surprisingly, ab initio emulsion polymerization led polymers with higher M n values than expected, unreacted X 44 at the end of the polymerization and quite high PDIs (∼6 at final conversion) that increased during polymerization [79]. This was attributed to a slow reaction of X 44 and slow nucleation of latex particles, probably due to a limited diffusion of X 44 across the aqueous phase. This disadvantage was circumvented by directly polymerizing BA with X 44 in nanosized droplets in the presence of a small amount of hydrophobe [88].…”

“…When treated in the presence of an alkoxide, followed by the addition of an alkyl halide, xanthates are readily obtained [6][7][8][9][10][11]. A variation of the latter procedure was reported by researchers from Noveon for making mono-and di-S-t-alkanoic acid terminated dithiocarbamates and xanthates (Scheme 10.9) [44,45]. In this method, the potassium salt of O-alkyl xanthate is reacted with chloroform and a ketone (acetone or cyclohexanone) under basic conditions, followed by acidic treatment to form an O-alkyl-S-α,α -disubstituted acetic acid dithiocarbonate.…”

Experimental Requirements for an Efficient Control of Free‐Radical Polymerizations via the Reversible Addition‐Fragmentation Chain Transfer (RAFT) Process

“…MMA [356] a) [357] Sty [356,358] AA [358] Oct a) [357] DBI [78] MeSty [358] MA [356] ABE a) [359] DCHI [78] EA [358] BA [123,258,345,358] a) [357,359] EHA [358] HEA [358] Am [103,360] tBAm [358] DMAm [360] …”

Photodimerization and Polymerization of PEG Derivatives through Radical Coupling using Photochemistry of Dithiocarbamate

“…Recently, improvement of living/control properties in the iniferter-based radical polymerization was performed by combination with reversible addition-fragmentation chain transfer (RAFT) [7][8][9] or selecting the irradiation wavelength. 10 Ultraviolet light (UV) irradiation of benzyl N,N-diethyldithiocarbamate (BDC), which is one of an iniferter, induces reversible radical dissociation reaction to generate benzyl radicals and dithiocarbamyl radicals ( Figure 1A, reaction I) but they are rapidly recombinated to regenerate BDC (reaction II).…”