Degradable PE-Based Copolymer with Controlled Ester Structure Incorporation by Cobalt-Mediated Radical Copolymerization under Mild Condition

Abstract

Polyethylene (PE) is one of the most widely used materials in the world, but it is virtually undegradable and quickly accumulates in nature, which may contaminate the environment. We utilized the cobaltmediated radical copolymerization (CMRP) of ethylene and cyclic ketene acetals (CKAs) to effectively incorporate ester groups into PE backbone as cleavable structures to make PE-based copolymer degradable under mild conditions. The content of ethylene and ester units in the produced copolymer could be finely regulated by CKA concentration or ethylene pressure. Also, the copolymerization of ethylene and CKA with other functional vinyl monomers can produce functional and degradable PEbased copolymer. All the formed PE-based copolymers could degrade in the presence of trimethylamine (Et 3 N).

Statistical and Block Copolymers of Ethylene and Vinyl Acetate via Reversible Addition‐Fragmentation Chain Transfer Polymerization

“…This was, however, not an impediment to already tune the architectures of the obtained VAE for the first time using a RDRP. [ 21–24 ]…”

“…On our side, we recently postulated that the synthesis of these well‐defined copolymers over the range of compositions depicting both EVA and VAE would be possible only with a system that controls the yet unachieved homopolymerization of E. Compared to VAc homopolymerization and copolymerizations of VAc with E, E homopolymerization additionally requires operating conditions compatible with the use of high pressures and for which the inherent irreversible chain transfer reactions are minimized. [ 25 ] Recently, in a study dedicated to the controlled copolymerization of E and cyclic ketene acetal, [ 24 ] CoMRP of E was briefly reported to be controlled without any side reaction at 75 °C using azobisisobutyronitrile (AIBN) and a Co(II) chain transfer agent (CTA) in a ratio of 6:1. Control homopolymerizations of E were indeed achieved for the first time by RAFT using dithiocarbonate [ 12 ] as controlling agents quickly followed by the use of TERP.…”

High Density Polyethylenes Bearing Isolated In-Chain Carbonyls

“…5,6 One potential solution to overcome the problem of the high chemical inertness of polyethylene plastics is to install a small amount of cleavable functional groups in the main chain of polyethylenes. 7 It is known that in-chain carbonyl units can enable chain scission through Norrish-type photochemical reactions. [8][9][10] Since the 1950s, radical copolymerization of ethylene and carbon monoxide (CO) to yield low-density polyketone materials was developed providing either alternating or ethylene rich non-alternating copolymers both with branched structures.…”

Polyesters by a Radical Pathway: Rationalization of the Cyclic Ketene Acetal Efficiency

“…[10] Ther ing-opening polymerization of cyclic ketene acetals (CKAs) by free radical or controlled radical mechanisms has attracted considerable interest since it presents an alternative route for the synthesis of functionalized aliphatic polyesters [12][13][14][15] and is ap owerful tool for imparting degradability to vinyl polymers [16][17][18][19][20] by introducing ester linkages into their backbone (Scheme 1b). [9,10] Indeed, the copolymerization of vinyl-based monomers and CKAs has been used to prepare (bio)degradable polyethylene, [21] fluoropolymers, [22] polymethyl methacrylate materials, [18] marine anti-biofouling coatings, [23,24] etc.,o ffering ap romising route to reduce plastic pollution. This approach has also been used to confer (bio)degradability to many vinyl-based biomaterials such as polymer prodrugs, [25] nanoparticles, [26,27] thermo-responsive materials, [20,28,29] icerecrystallization inhibitors, [30] etc.…”