Mild and Efficient Preparation of Block and Gradient Copolymers by Methanesulfonic Acid Catalyzed Ring-Opening Polymerization of Caprolactone and Trimethylene Carbonate

Polycaprolactone/polytrimethylene carbonate copolymers of different microstructures have been prepared in toluene solution under mild conditions by controlled ring-opening polymerization of ε-caprolactone and trimethylene carbonate with methanesulfonic acid as catalyst. Sequential addition of the monomers led to the formation of well-defined di- and tri-block copolymers, demonstrating the ability of the catalytic system to cross-propagate. Simultaneous copolymerization yielded gradient copolymers as a result of the different copolymerization reactivity ratios and absence of undesirable redistribution reactions. DSC analyses showed a noticeable impact of the copolymer microstructure on the thermal properties

5‑Methylene-1,3-dioxane-2-one: A First-Choice Comonomer for Trimethylene Carbonate

5-Methylene-1,3-dioxane-2-one (exTMC), a six-membered ring cyclic carbonate bearing an exocyclic methylene group, has been investigated as comonomer for trimethylene carbonate (TMC) with the aim to prepare functionalized polycarbonates. Using methane sulfonic acid (MSA) as an organocatalyst, exTMC and TMC copolymerize in a controlled manner to lead to copolymers of adjusted composition and high randomness (the corresponding reactivity ratios have been determined by the Beckingham–Sanoja–Lynd (BSL) method as 0.93–0.95 and 1.04–1.07 for exTMC and TMC, respectively). Subsequent thiol-ene reaction on the exomethylene group with thioglycolic acid or thioglycerol provides aliphatic polycarbonates with adjustable amounts of COOH or OH groups randomly distributed along the polymer chains

5‑Methylene-1,3-dioxane-2-one: A First-Choice Comonomer for Trimethylene Carbonate

5-Methylene-1,3-dioxane-2-one (exTMC), a six-membered ring cyclic carbonate bearing an exocyclic methylene group, has been investigated as comonomer for trimethylene carbonate (TMC) with the aim to prepare functionalized polycarbonates. Using methane sulfonic acid (MSA) as an organocatalyst, exTMC and TMC copolymerize in a controlled manner to lead to copolymers of adjusted composition and high randomness (the corresponding reactivity ratios have been determined by the Beckingham–Sanoja–Lynd (BSL) method as 0.93–0.95 and 1.04–1.07 for exTMC and TMC, respectively). Subsequent thiol-ene reaction on the exomethylene group with thioglycolic acid or thioglycerol provides aliphatic polycarbonates with adjustable amounts of COOH or OH groups randomly distributed along the polymer chains