Synthesis and Characterization of Biobased Polyesters with Tunable T-g by ROCOP of Beta-Elemene Oxides and Phthalic Anhydride

The use of terpene-based oxides derived from beta-elemene is reported in the context of new functional semiaromatic polyester development. In particular, poly(beta-elemene monoxide-alt-phthalic anhydride) featuring two double bonds per repeating unit having distinct reactivity is conveniently prepared by iron- and aluminum-mediated ring-opening polymerization (ROCOP). Sequential and selective transformation of each of these double bonds is addressed by epoxidation allowing one to precisely manipulate the degree and nature of the functionality in the polymer backbone while modulating the T-g from 68 to 121 degrees C. Direct access to cross-linked polyesters is demonstrated by ROCOP of bifunctional beta-elemene dioxide and phthalic anhydride furnishing a material with a Tg of 125 degrees C.