Ring opening insertion polymerization of ε‐caprolactone with hydrogen phosphonate initiators

Abstract

In this work, ring opening insertion polymerization (ROIP) of ε‐caprolactone (ε‐CL) using a series of hydrogen phosphonates (H‐phosphonates) as initiators was investigated. The ROIP occurred by a coordination‐insertion mechanism containing two steps. First, the carbonyl carbon was attacked by the phosphorus atom of the H‐phosphonate tautomerization (a phosphine‐like structure) and the acyl‐oxygen bond was broken. An intermediate was formed by the coordination of the former carbonyl carbon and acyl‐oxygen of ε‐CL to phosphorus atom. Then the phosphorus‐alkoxide of H‐phosphonate was cleavaged to form acyl‐alkoxide bond. Poly(ε‐caprolactone) (PCL)‐inserted H‐phosphonates (PCL‐HPs), which was not only the product of the occurred ROIP but also the initiator for the next ROIP, were produced. After 60 min of microwave irradiation (510 W), PCL with a number‐average molar mass of 7800 g/mol and monomer conversion over 92% was obtained. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6214–6222, 2009

Microwave-assisted polymer synthesis (MAPS) as a tool in biomaterials science: How new and how powerful

“…The derivatives obtained are suitable for a broad spectrum of bio(pharmaceutical) applications, such as particles, monolithic implants and scaffolds. Finally, a different kind of initiator, hydrogen phosphonates (e.g., diisopropyl hydrogen phosphonate), has been explored [84]. The mechanism of the reaction is more complex and comprises two stages: (i) coordination and (ii) insertion; the reaction is known as ring opening insertion polymerization (ROIP).…”

Green Polymer Synthesis: An Overview on Use of Microwave‐Irradiation

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One‐Pot Synthesis of Polyester–Polyolefin Copolymers by Combining Ring‐Opening Polymerization and Carbene Polymerization

“…In this work, copolymers with the structure of polyester and polyolefin were synthesized in one‐pot by combining CP and ROP. Due to the advantages of microwave heat­ing, such as instantaneous/rapid heating, temperature homogeneity, and energy saving, the reaction was carried out under microwave irradiation . In this reaction, alkyl acetate carbene (ROCOCH:) generated from diazoacetate acts as organocatalyst, which enables the ROP of cyclic ester.…”