Copolymerization of vinyl acetate with 1‐octene and ethylene by cobalt‐mediated radical polymerization

Abstract

The cobalt‐mediated radical polymerization of vinyl acetate was extended to copolymerization with 1‐alkenes (ethylene or 1‐octene). In agreement with the low amount of 1‐alkene that could be incorporated into the copolymer, a gradient structure was predictable, but a rather low polydispersity was observed. A poly(vinyl acetate)‐b‐poly(octene) copolymer was also successfully synthesized, leading to a poly (vinyl alcohol)‐b‐poly(octene) amphiphilic copolymer upon the methanolysis of the poly (vinyl acetate) block. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2532–2542, 2007

New Phenomena in Organometallic‐Mediated Radical Polymerization (OMRP) and Perspectives for Control of Less Active Monomers

“…As mentioned in a previous section, the [Co(acac) 2 ] system exerts a certain extent of control even for simple olefins (1‐octene, ethylene) 33. 56 Statistical VAc/olefin copolymers were well controlled, but 1‐octene homopolymerization from a [PVAcCo(acac) 2 ] macroinitiator yields only short chains (degree of polymerization or D.P.=4) before termination, presumably by degradative chain transfer 33. This result, however, shows that even the stronger bond with secondary and primary (for ethylene) alkyls can be reactivated for [RCo III (acac) 2 ].…”

“…Here again, low‐temperature conditions are expected to help. Indeed, moderate success has been reported for the OMRP of ethylene and 1‐octene near room temperature 33. Strong radicals may also attack the metal complex at one of the ligands rather than at the metal center.…”

Cobalt‐Mediated Radical Polymerization of Acrylonitrile: Kinetics Investigations and DFT Calculations

“…Under these conditions, poly(acrylonitrile) with a predictable molar mass and molar mass distri-using a [PVAc-CoA C H T U N G T R E N N U N G (acac) 2 ] macroinitiator preformed by CMRP. Among the co-monomers used are styrene, [17,18] octene, [19] ethylene, [19] N-vinyl pyrrolidone, [20] and more recently acrylonitrile (AN). [21] In this last case, the controlled character of AN polymerization initiated at 0 8C from the PVAc macroinitiator was clearly established provided that dimethylformamide (DMF) was used as the solvent.…”

Cobalt‐Mediated Radical Polymerization

“…Hydrolysis of both the esters and the nitrile groups of the PVAc-b-PAN copolymers paved the way to a well-defined, pH-sensitive PAA-b-PVA compound [48,50]. Despite the low polyolefin content of the final material, 1-octene was used successfully as the comonomers of VAc in the block, and statistical radical polymerization processes were carried out in the presence of cobalt complexes [51]. Moreover, the resumption of styrene polymerization from a PVAc-Co(acac) 2 macroinitiator was also considered, which led to the expected PVAc-b-polystyrene (PS) copolymer; unfortunately, however, a poor control of the styrene block was observed in this case [52].…”