Radical Copolymerization of Vinyl Ethers and Cyclic Ketene Acetals as a Versatile Platform to Design Functional Polyesters

Abstract

Free-radical copolymerization of cyclic ketene acetals (CKAs) and vinyl ethers (VEs) was investigated as an efficient yet simple approach for the preparation of functional aliphatic polyesters.T he copolymerization of CKA and VE was first predicted to be quasi-ideal by DFT calculations.The theoretical prediction was experimentally confirmed by the copolymerization of 2-methylene-1,3-dioxepane (MDO) and butyl vinyl ether (BVE), leading to r MDO = 0.73 and r BVE = 1.61. We then illustrated the versatility of this approach by preparing different functional polyesters:1 )copolymers functionalized by fluorescent probes;2)amphiphilic copolymers grafted with poly(ethylene glycol) (PEG) side chains able to self-assemble into PEGylated nanoparticles;3 )antibacterial films active against Gram-positive and Gram-negative bacteria (including amultiresistant strain);and 4) cross-linked bioelastomers with suitable properties for tissue engineering applications.

Radical Ring-Opening Copolymerization-Induced Self-Assembly (rROPISA)

“…33,34 Recent years have seen a resurgence of interest in CKAs, which may be explained, at least in part, by their ability to copolymerize with traditional vinyl monomers (e.g., vinyl acetate, methacrylic esters) by both conventional free-radical polymerization and RDRP techniques. [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] However, to the best of our knowledge, there is no example of PISA systems or emulsion/dispersion (co)polymerizations based on CKAs. Only two related studies have been published so far.…”

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

“…The MDO monomer was commonly used to be copolymerized with vinyl monomers via radical mechanism for preparing degradable polymers (Hedir et al, 2014(Hedir et al, , 2015(Hedir et al, , 2017Undin et al, 2014); the product of ringopening polymerization of MDO has ester group in its backbone, which could easily degrade in acidic or basic conditions (Agarwal, 2010;Hill et al, 2017Hill et al, , 2018Tardy et al, 2017b;Undin et al, 2012). The MDO propagating radicals lack stabilized group and generally result in unfavorable reactivity ratios toward more-activated monomers, usually leading to very limited incorporation in the final copolymer when copolymerizing with more-activated monomers (Seema and Liqun, 2009;Undin et al, 2013); however, the copolymerization of MDO and less-activated monomers (e.g., vinyl acetate, vinyl ethers) could yield statistical copolymers (Hedir et al, 2017;Tardy et al, 2017a). In our work, Co II (Salen*)-mediated radical homopolymerization of MDO using AIBN as the initiator at 75 C was carried out.…”

“…Therefore, the synthesis of degradable PE-based copolymer that is kind to environment is a major goal of chemists. Ideally, introducing cleavable structures into the main chain of PE could make PE degradable (Tardy et al, 2017a(Tardy et al, , 2017b. In 1980s, the copolymerizations of ethylene and carbon monoxide or vinyl ketone monomers have been employed to introduce carbonyl groups into the copolymer.…”

Responsive Polyesters with Alkene and Carboxylic Acid Side-Groups for Tissue Engineering Applications

“…However, these methods involve either a complex multistep synthetic route or a reaction performed under very strict conditions. Recently, the synthesis of functional polyesters via the radical ring-opening copolymerization of cyclic ketene acetals with conventional vinyl monomers was reported [ 12 , 13 ]. Furthermore, polyesters with reactive side groups have been synthesized by scalable synthetic methods, i.e., the step-growth polymerization of difunctional comonomers.…”