Tuning the thermal properties of poly(ethylene)-like poly(esters) by copolymerization of ε-caprolactone with macrolactones, in the presence of a pyridylamidozinc(II) complex

ABSTRACT Linear aliphatic poly(ester)s, as thermoplastic materials, are more and more envisaged as the potential “green” alternative to traditional plastics. Aliphatic polyesters having long methylene chain behave as “polyethylene-like” materials and can be prepared by ring-opening polymerization (ROP) of macrolactones. A pyridylamidozinc(II) complex was used for the ROP of ε-caprolactone (CL) and of two large ring size lactones, the ω-6-hexadecenlactone (6HDL) and the ω-pentadecalactone (PDL). High turnover frequencies were observed for the CL polymerization, while for the macrolactones, an entropy-driven behavior was recognized. Random copolymerizations of the PDL with 6HDL and of the macrolactones with CL were successfully achieved, and the copolymer microstructure was ascertained by NMR and MALDI analyses. The copolymer melting temperatures, measured by DSC, and the thermal degradation behavior, studied by TGA in nitrogen and air atmosphere, were dependent on the copolymer's composition. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020, 58, 528–539