Recently, we have developed an eco-friendly method for the preparation of a renewable dicarboxylic acid 2,5-furandicarboxylic acid (FDCA) from biomass-based 5-hydroxymethylfrufural (HMF). In the present work, we optimized our reported method, which used phosphate buffer and Fe(OH)3 as the stabilizer to improve the stability of potassium ferrate, then got a purified FDCA (up to 99%) in high yield (91.7 wt %) under mild conditions (25 °C, 15 min, air atmosphere). Subsequently, the obtained FDCA, along with 1,6-hexanediol (HDO), which was also made from HMF, were used as monomers for the synthesis of poly(hexylene 2,5-furandicarboxylate) (PHF) via direct esterification, and triphenyl phosphite was used as the antioxidant to alleviate the discoloration problem during the esterification. The intrinsic viscosity, mechanical properties, molecular structure, thermal properties, and degradability of the PHFs were measured or characterized by Koehler viscometer, universal tensile tester, Nuclear Magnetic Resonance (NMR), Fourier-transform Infrared (FTIR), X-ray diffraction (XRD), Differential Scanning Calorimeter (DSC), Derivative Thermogravimetry (DTG), Scanning Electron Microscope (SEM), and weight loss method. The experimental evidence clearly showed that the furan-aromatic polyesters prepared from biomass-based HMF are viable alternatives to the petrochemical benzene-aromatic polyesters, they can serve as low-melting heat bondable fiber, high gas-barrier packaging material, as well as specialty material for engineering applications.

The pulp and paper industry is the largest industrial sector that converts wood-based materials into fibre-related products. It is common for pulp fibre plugs to develop within pipelines and equipment causing operational downtime, which ultimately requires the use of costly procedures for plug removal. In this study, a laboratory-scale set-up was developed to measure the breakup pressure of pre-formed plugs to indicate the plug (fibre network) strength. A cupriethylenediamine (CED) solution was investigated with regards to its ability to decrease the plug strength. When the concentration of the CED solution is 0.1 M or lower, the plug breakup pressure increases due to fibre swelling. Conversely, when the CED concentration is 0.2 M or greater, the plug breakup pressure decreases significantly due to partial fibre dissolution.