Synthesis and enzymatic degradation of 2‐methylene‐1,3‐dioxepane and methyl acrylate copolymers

Abstract

Copolymers of 2‐methylene‐1,3‐dioxepane (MDO) and methyl acrylate (MA) containing ester units both in the backbone and as pendant groups were synthesized by free‐radical copolymerization. The influence of reaction conditions such as the polymerization time, temperature, initiator concentration, and comonomer feed ratio on the yield, molecular weight, and copolymer composition was investigated. The structure of the copolymers was confirmed by 1H NMR, 13C NMR, and IR spectroscopy. Differential scanning calorimetry indicated that the copolymers had a random structure. An NMR study showed that hydrogen transfer occurred during the copolymerization. The reactivity ratios of the comonomers were rMDO = 0.0235 and rMA = 26.535. The enzymatic degradation of the copolymers obtained was carried out in the presence of proteinase K or a crude enzyme extracted from earthworms. The experimental results showed that the higher ester molar percentage in the backbone caused a faster degradation rate. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2898–2904, 2003

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

“…The unfavorable reactivity ratios of CKAs with traditional vinyl monomers indeed leads to considerable discrepancy between the incorporated fraction of CKA in the copolymer and its initial fraction in the monomer feed. It results in a non‐statistical and thus inhomogeneous incorporation of CKA along the chain (for example, the reactivity ratio between MDO and methyl acrylate (MA) was measured as r MDO =0.023 and r MA =26.53). The particular reactivity of CKAs was explained by the strong nucleophilicity of the double bond.…”

Simulation of the Degradation of Cyclic Ketene Acetal and Vinyl‐Based Copolymers Synthesized via a Radical Process: Influence of the Reactivity Ratios on the Degradability Properties

“…It is here important to note that in the case of the rROP of styrene or methacrylate vinyl monomers with MDO, the incorporation of the CKA monomer in the final copolymer is very weak (i.e., the mole fraction of CKA units in the copolymer, F CKA is always lower than the mole fraction of CKA in the feed, f CKA ). This phenomenon can be explained by the strong difference between the vinyl and CKA reactivity ratios (r vinyl and r CKA , respectively) with r CKA values generally very low (and close to 0) compared to the r vinyl ones (e.g., r MDO = 0.023 and r MA = 26.53 [16] ; r MDO = 0.021 and r S = 22.6; [17] r MDO = 0.04 and r MMA = 3.5 [18] ). The only noticeable exceptions concern the systems MDO/VAc [14] and MDO/VE [12] with reactivity ratios both close to 1 (r VE = 1.61 and r MDO = 0.73; r VA = 1.53 and r MDO = 0.47).…”

Preparation of fine particles of poly(N-vinyl-2-pyrrolidone-co-2-methylene-1,3-dioxepane) using supercritical antisolvent

“…MDOP can copolymerize with vinyl monomers by convenient free radical to obtain copolymers with biodegradable poly(-caprolactone) units in the backbone chain. Some research groups studied about synthesis of copolymers of MDOP and other monomer [5][6][7]. In our lab copolymer of MDOP with N-vinyl-2-pyrrolidone (NVP) was synthesized [8].…”

“…Schematic diagram of the experimental apparatus: (1) carbon dioxide bomb, (2) filter, (3) heat exchanger, (4) high pressure pump, (5) relief valve,(6) precipitator, (7) back pressure regulator, (8) high pressure pump, (9) solution reservoir, (10) separator.…”