High-Performance Thermoplastics from a Unique Bicyclic Lignin-Derived Diol

Polyesters are an important class of thermoplastic polymers, and there is a clear demand to find high-performing, recyclable, and renewable alternatives. In this contribution, we describe a range of fully bio-based polyesters obtained upon the polycondensation of the lignin-derived bicyclic diol 4,4 '-methyl-enebiscyclohexanol (MBC) with various cellulose-derived diesters. Interestingly, the use of MBC in combination with either dimethyl terephthalate (DMTA) or dimethyl furan-2,5-dicarboxylate (DMFD) resulted in polymers with industrially relevant glass transition temperatures in the 103-142 degrees C range and high decomposition temperatures (261-365 degrees C range). Since MBC is obtained as a mixture of three distinct isomers, in-depth NMRbased structural characterization of the MBC isomers and thereof derived polymers is provided. Moreover, a practical method for the separation of all MBC isomers is presented. Interestingly, clear effects on the glass transition, melting, and decomposition temperatures, as well as polymer solubility, were evidenced with the use of isomerically pure MBC. Importantly, the polyesters can be efficiently depolymerized by methanolysis with an MBC diol recovery yield of up to 90%. The catalytic hydrodeoxygenation of the recovered MBC into two high-performance specific jet fuel additives was demonstrated as an attractive end-of-life option.

Automated summary

Polyesters obtained from the polycondensation of lignin-derived bicyclic diol with cellulose-derived diesters showed high-performance properties and potential applications. The use of isomerically pure diol resulted in significant effects on the physical properties of the polyesters. Furthermore, the efficient depolymerization of the polyesters and conversion into high-performance jet fuel additives was demonstrated.