This study presents a novel process of wood modification employing humins, i.e. polydisperse furanic macromolecules formed during sugar dehydration. Humin valorization is more and more in the spotlight, thanks to the increased research efforts being placed by industries on biomass valorization. Here, a water soluble liquid fraction of humins was employed to impregnate wood and was polymerized within the wood using heat. This so-called 'humination' process was compared with the more classical furfurylation, which consists of impregnating with furfuryl alcohol (FA), and the polymerization of FA inside the wood.Confocal laser scanning fluorescence microscopy proved that furanic entities contained in the liquid fraction of humins polymerized within the wood cell walls and resulted in fluorescence similar to that seen for furfurylated wood. The humin modified wood showed lower mass increase and identical dimensional stability compared to furfurylated wood after immersion in water. Both treatments resulted in higher hydrophobicity compared to untreated wood. The elastic modulus of humin treated wood, measured by dynamic mechanical analysis (DMA), was similar to that of furfurylated wood for T < 75°C and slightly higher than untreated wood. Finally, reaction-to-fire properties were investigated. Humin treated wood showed some advantages over furfurylated wood such as longer ignition time, slower heat release rate (−13%) and lower CO formation. This study demonstrates for the first time that humins can be used as an alternative to FA for wood modification to obtain enhanced wood products. † Electronic supplementary information (ESI) available. See

Sintering has been achieved by Spark Plasma Sintering at low temperatures (<400 °C) and relatively high pressures (300 to 600 MPa) for various thermodynamically fragile compounds (carbonates, sulfate, and phosphate) decomposing between 220 and 780 °C.

Humins is a biomass-derived material, co-product of the acid-catalyzed conversion of cellulose and hemicellulose to platform chemicals. This work presents a thorough study concerning the crosslinking kinetics of humins by chemorheological analysis and model-free kinetics under isothermal and non-isothermal curing. Humins can auto-crosslink under the effect of temperature, and the reaction can be fastener when adding an acidic initiator. Thus, the effect of P-Toluenesulfonic acid monohydrate (pTSA) on the crosslinking kinetics was also studied. The dependencies of the effective activation energy (Eα-dependencies) were determined by an advanced isoconversional method and correlated with the variation of complex viscosity during curing. It is shown that humins curing involves multi-step complex reactions and that the use of an acidic initiator allows faster crosslinking at lower temperatures, involving lower Eα. The shift from chemical to diffusion control was also estimated.

Conversion of lignocellulosic biomass often brings about the formation of several side products. Among these, a black and viscous coproduct known as humins is formed on acidic treatment of polysaccharides. To improve the efficiency of this process from an economical and environmental perspective, new solutions for humins valorization are urgently needed. This work focuses on the comprehensive understanding of humins with special emphasis on their structure/properties relationships. Humins were subjected to different thermal treatments and characterized by means of structural, thermoanalytical, and rheological investigations. The structure and composition of humins are very diverse and depend on the thermochemical conditions. On sufficient heating, humins change into a nonreversible and more branched furanic structure with a relatively high glass‐transition temperature (Tg>65 °C). Thus, humins can be easily processed for preparing thermoset‐like resins.

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Cool-SPS conditions (low temperature/high pressure) can be used to densify materials with limited thermodynamical stability, due to low temperature phase transition, melting, decomposition… We recently demonstrated the potential of SPS for the stabilization and densification of diversified materials at very low temperatures. Here we report the sintering of a potentially magnetoelectric pyrophosphate with low temperature decomposition. Characterization of its magnetic properties are presented, and dielectric/magnetoelectric characterization could also be performed thanks to the high densification obtained at temperatures as low as 200 °C.

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We report here the synthesis and densification of two magnetic materials in the system A2Cu(CO3)2 (A = Na, K).