Unsaturated biobased polyesters from bicyclic α ‐pinene‐based diols

Abstract Here we report the synthesis and characterization of a set of four unsaturated prepolymers made from polycondensation of two (−)‐α‐pinene‐derived bulky diols, trans ‐hydroxy nopol (HN) and trans ‐hydroxy myrtenol (HM), with dimethyl itaconate and dimethyl maleate as renewable acyl donors. Structure verification by 1 H and 13 C NMR in concert with Fourier transform infrared analyses confirmed intact backbone C=C groups and ester formation in these prepolymers, showing number‐average molar masses between 1.4 and 6.3 kg mol −1 and dispersity in the range 1.3–2.2. The intact pinene core concomitant with the chiral arms protruding from it results in elevated thermal stability, manifested by 5% weight‐loss temperatures ( T ₅) above 220 °C and decomposition maxima reaching 315 °C, concomitant with an elevated glass transition temperature for one of the materials ( T g of 45 °C). Finally, to investigate end‐of‐life options, subjecting the four polymers to depolymerization studies using the leaf‐branch compost cutinase resulted in partial depolymerization for the less flexible maleate‐containing polyesters, liberating the corresponding diol monomers (8% HN and 13.5% HM). Biodegradation was further supported by shifted SEC traces toward lower molar mass. Complementary in silico docking and metadynamics studies were used to identify near‐attack conformations in which the ester carbonyl in the cis ‐alkene‐containing, maleate‐based bulky backbones is ready for hydrolysis. Overall, this study highlights the untapped potential to generate biobased unsaturated polyesters by capitalizing on rigid bicyclic terpene‐based diols, resulting in elevated thermal performance while retaining enzymatic degradability. © 2026 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.