Cross-linking reaction of diastereomeric bis-limonene oxide with polyhydric carboxylic acid

In this study, the epoxy-carboxylic acid reaction was examined using two diastereomers of biobased bis-functional epoxides (bis-trans-LO and bis-cis-LO derived from trans- and cis-limonene oxide, respectively) and polyhydric carboxylic acid. The network polymers derived from bis-trans-LO had a higher polymer yield as well as superior thermal properties and mechanical strength than those derived from bis-cis-LO, since bis-trans-LO was cross-linked effectively owing to the direct nucleophilic attack on the methine carbon of the epoxy ring by carboxy groups. The reprocessability of the network polymer in the presence of Zn(acac)(2) was confirmed in both cases, whereas the tensile strength decreased after the 2nd cycle.