Green synthesis and characterization of a wholly bio-based self- healing polyester elastomer and its graphene nanocomposites

A new wholly bio-based polyester elastomer (PEE) was synthesized by one-pot condensation polymer-ization of a fatty diol and a mixture of a fatty tricarboxylic acid and a fatty dicarboxylic acid, all con-taining multiple alkyl chains, without the use of any solvent or toxic additive. The elastomer shows excellent resilience with low hysteresis, which could fully recover its original state from 200% strain within 5 s. Owing to strong van der Waals interaction among abundant dangling alkyl chains, the polyester elastomer possesses autonomous self-healing behavior at ambient temperature without any external intervention, capable of restoring 96.8% of its original Young's modulus and 52.1% of its original elongation at break within 10 min. Graphene oxide (GO) reduced and modified by p-phenylenediamine (PPD) was used to improve the mechanical properties of PEE to broaden its applications. By incorporating with low loadings of PPD-reduced GO (P-rGO), the Young's modulus, tensile strength, elongation at break and energy at break of PEE are all enhanced, with 0.5 wt% being the optimal loading. However, the self -healing efficiency is reduced by addition of P-rGO due to the restriction of polymer chains. This type of renewable elastomer and its nanocomposites have potential in a variety of applications.(c) 2023 Elsevier Ltd. All rights reserved.