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Sustainable Polycarbonates from a Citric Acid-Based Rigid Diol and Recycled BPA-PC: From Synthesis to Properties

Here we present a series of homopolycarbonates (homo-PCs) and copolycarbonates (co-PCs) based on a novel bicyclic diol octahydro-2,5-pentalenediol (OPD) from naturally occurring citric acid and bis(hydroxyethyl ether) of bisphenol A (BHEEB), synthesized by melt polycondensation. The recently developed OPD has been shown to be a highly rigid and thermally stable building block suitable for the construction of performance polymers. BHEEB, which was obtained from the chemical recycling of BPA-PC, was used to compensate for the low reactivity of OPD and to modify the brittleness of polycarbonate (PC) solely based on OPD, without compromising other properties. The single crystal of the endo-endo isomer of OPD was deliberately obtained, and its absolute stereochemistry was unambiguously identified by single-crystal X-ray diffraction for the first time. The polymers had Mn in the 10 100–20 000 g mol–1 range and gradually decreased with increasing OPD content. NMR analyses revealed the random structures of the co...