Designed enzymatically degradable amphiphilic conetworks by radical ring-opening polymerization

Abstract

A new route for the preparation of enzymatically degradable amphiphilic conetworks (APCNs) based on unsaturated polyesters by radical ring-opening copolymerization of vinylcyclopropane (VCP) with cyclic ketene acetal (CKA) is presented in this article. In the first step, the unsaturated biodegradable polyesters with random distribution of cross-linkable double bonds and degradable ester units were prepared by radical ring-opening copolymerization of VCP and CKA such as 2-methylene-4-phenyl-1,3-dioxolane (MPDO). Very similar reactivity ratios (r VCP = 0.23 ± 0.08 and r MPDO = 0.18 ± 0.02), unimodal gel permeation chromatography (GPC) curves and 2D NMR technique (heteronuclear multiple bond correlation, HMBC) showed the formation of random copolymers with unsaturation and ester units. The unsaturated units were used for cross-linking by radical polymerization with a hydrophilic macromonomer (oligo (ethylene glycol) methacrylate, OEGMA) in a second step for the formation of enzymatically degradable amphiphilic conetworks (APCNs). Enzymatic degradability was studied using Lipase from Pseudomonas cepacia. Due to the hydrophilic (HI) and hydrophobic (HO) microphase separation, the APCNs showed swelling in both water and organic solvents with different optical properties. The method provides an interesting route for making functional biodegradable APCNs using radical chemistry in the future by choosing appropriate vinyl comonomers. † Electronic supplementary information (ESI) available: Homopolymerization and characterization of VCP and reactivity ratio calculations. See

PLMA‐b‐POEGMA amphiphilic block copolymers: Synthesis and self‐assembly in aqueous media

“…24 8C corresponds to the melting (T m ), of the side chains of the POEGMA block. 32 The T g of POEGMA cannot be determined safely because this transition is overlapped by the melting of the POEGMA side chains. Nevertheless, this transition is expected in the temperature range of 245 8C to 225 8C, 33 where a change in the baseline is also observed in the thermograms of the PLMA-b-POEGMA copolymers (Fig.…”

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

“…Radical ring-opening polymerization (rROP) presents the advantages of both ring-opening polymerization and radical polymerization, specifically the production of (co)polymers with the possibility to insert heteroatoms and/or functional groups into the main chain by facile polymerization procedures (Scheme 1a). [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.…”

Radical ring-opening polymerization of novel azlactone-functionalized vinyl cyclopropanes

“…This characteristic makes them attractive as low-shrinking components in dental adhesives, [3][4][5] curing resins and (bio)material applications. 6 Another interesting aspect of VCP monomers is that during rROP two distinct propagation pathways take place which give rise to poly(vinyl cyclopropane) (PVCP) with either unsaturated linear repeating units or saturated cyclic repeating units, or a mixture of both. [7][8][9] The linear repeating units possess unsaturated bonds which have been successfully used for radical thiol-ene post-polymerization modifications.…”