One-pot strategy to access dynamic dual network from lignin-initiated star polymers by side reaction and transesterification

Abstract

The star–star coupling is often regarded as an undesirable side reaction in in the synthesis of star polymers. To mitigate this issue, strategies such as operating at low temperatures, maintaining low monomer concentrations, and limiting monomer conversion are typically employed, albeit at the cost of reduced synthetic efficiency in producing the desired polymer materials. In this study, we propose a novel approach to harness this side reaction for the creation of a lignin-containing, sustainable, and solvent-resistant dynamic dual network using a one-pot synthesis strategy. Initially, a lignin-based macroinitiator with low polydispersity index (PDI) was synthesized to facilitate the precise formation of well-defined star polymers functionalized with epoxy groups. Subsequent to this, the first network, composed of star-shaped lignin-grafted copolymers, was successfully established through the utilization of the free radical bimolecular termination reaction. Following this, the second dynamic crosslinked network was formed via vitrimer chemistry between epoxy and carboxylic acid. The resulting dynamic dual network, accessible through a straightforward one-pot method, exhibited excellent reprocessability and solvent resistance, rendering it suitable for applications as high-performance adhesives. This study introduces a novel strategy for the synthesis of dynamic dual networks based on star-shaped lignin-grafted copolymers, offering promising prospects for the advancement of sustainable biomaterial synthesis.