Cross-linked polyfuran networks with elastomeric behaviour based on humins biorefinery by-products†
Biorefinery by-products have received much attention in the last few years. Humins are one of these candidates. Nevertheless, one common feature of humins, as a polyfuranic thermoset material, is their inherent brittleness which is a direct consequence of the network's structure. Auto-crosslinked humins networks exhibit only minor deformation and break very easily. Consequently, this behavior limits their use in many industrial applications. For this reason, we used in this work the copolymerization strategy, by combining humins with epoxide based aliphatic ethers, as a toughening approach. To gain a fundamental understanding of the humins based copolymers we thoroughly investigated their structure, behavior and properties by FT-IR, rheology, DSC, TGA, DMA and tensile tests. These investigations show one of the most important results: the humins copolymers have a ductile and elastomeric character. The tensile strain at break of the copolymers reaches ≈60% which is a significant advantage in terms of applications of humins as structural materials. To our knowledge, these are the first data reported on the synthesis of elastomeric humins based copolymers paving the way for the utilization of these emergent materials in industrial applications.