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Driven by the global carbon neutrality action, biomass-derived functional materials have been applied in many fields to alleviate the pressure brought by the depletion of fossil energy. However, due to the complex structure, lignin faces many difficulties in its high-value utilization. The second largest biomass in the world has become the largest "natural waste". In this paper, the lignin-based biochar-silica (LB-S) hybrid nanoparticles were prepared via a combination of two-step acid precipitation and carbonization using lignin black liquor extracted from xylose residue and sodium silicate as raw materials. The effects of carbonization temperature and lignin-based biochar (LB) content on the reinforcing properties of LB-S were studied. The results show that the particle size, specific surface area, pore characteristics, and surface polarity of LB-S all affect the mechanical properties of the final vulcanizates. The reinforcement performance of the best sample (L M B 500 -S) with "high structure" characteristics can be comparable to that of commercial carbon black (CB) N550. This study shows that L M B 500 -S hybrid nanoparticles with economic benefits possess the potential to completely replace commercial CB, which can turn lignin waste into treasure and promote the green development of traditional rubber industry in the context of carbon neutrality., Competing Interests: Declaration of competing interest The authors declared no conflicts of interest., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Due to the complex network of aromatic units, lignin is difficult to achieve high-value applications in the industrial field, becoming the largest "natural waste". In this paper, dual-phase fillers with excellent rubber reinforcement were prepared from lignin and sodium silicate through the method of controllable two-step acid precipitation without any complicated modification. During the formation of hybrid nanoparticles, silica nanoparticles were formed as templates in the first step, and then lignin was used as coating agent to bind with silica. The size and morphology of products could be easily adjusted by changing acid precipitation conditions. The L 60 S S hybrid nanoparticles with the best reinforcement performance showed the ability to replace carbon black (CB) in a high proportion. In addition, LS RH -S hybrid nanoparticles made from rice husk black liquor had similar physical and chemical properties and excellent reinforcement properties to L 60 S S . Even if the ratio of each component of the raw material was different, the product could be flexibly controlled by the two-step acid precipitation to obtain the expected properties. The wide applicability of this method in many extraction processes based on alkaline procedures was proved, and it provided a basis for the process design of comprehensive utilization of biomass. This work will promote the application of lignin in high-value fields, and the sustainable development of the rubber industry by utilizing agricultural waste was achieved., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Biomass derived fillers have been developed as sustainable substitution of carbon black (CB) used in rubber industry to reduce the dependence on fossil fuels. Lignin is the abundant component of biomass, but has poor reinforcing performance due to its huge particle size. In this work, we prepared a lignin/silica (LS) hybrid material from rice husks via a facile self-assembly method. The formation of LS cut lignin macromolecules into fragments and resulted in a small average particle size of 320 nm. When LS was filled into the natural rubber to substitute 10 phr CB, both filler-filler interaction and filler-rubber interaction were enhanced compared with the single use of CB. In consequence, the obtained 10LS/40CB/NR vulcanizates showed overall improvement in tensile strength, tear strength and abrasion resistance compared with the 50CB/NR vulcanizates. For the sustainable development of rubber industry, the natural LS hybrid material with low production cost is a promising reinforcing filler for the partial replacement of CB., Competing Interests: Declaration of competing interest The authors declared no conflicts of interest., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Lignin, a by‐product produced during pulping and papermaking, is a phenol‐rich compound with excellent prospect to be used as a substitute for phenol in phenolic resin adhesive. Phenol‐enriched hydroxy depolymerized lignin by microwave alkali catalysis is an effective method to prepare high‐adhesive biomass composite. This study investigated the microwave digestion of lignin under different conditions of the alkali catalysis (sodium hydroxide) concentration, power, reaction time, and reaction temperature. The results show that on the condition of sodium hydroxide concentration of 0.3 mol/L, temperature of 170 °C, and time of 20 min, the highest phenolic hydroxy content obtained by depolymerization of lignin is 21.68%. SEM shows that the depolymerized lignin has no original basic constituent units and lignin‐based phenolic resin has dense uniform pine needle units. Therefore, it has a high bonding strength of 1.934 MPa. The bonding strength and phenol content obtained by the microwave depolymerization method are much higher than those of other modification methods. [ABSTRACT FROM AUTHOR]

In the present work, lignin was isolated from pulping black liquor. Selective precipitation was achieved by adding hydrochloricacid to adjust pulping black liquor pH from 1 to 5. Reaction pH, reaction temperature and the content of lignin were investigated in the total process. A considerable increase in the amount of precipitate was observed while pH was decreasing. Lignin obtained from pulping black liquor had been used as the reactant to partly replace bisphenol A in preparing epoxy resins with different lignin additives at 90 °C. The mechanical and the thermal properties of cured lignin‐based epoxy resins were compared with those at different contents of lignin and reaction temperatures with ethylenediamine as the curing agent. The cured lignin‐based epoxy resins with 20 wt. % lignin at 90 °C showed the highest viscosity up to 396 MPa⋅s. We had successfully got good performance lignin‐based epoxy resin. [ABSTRACT FROM AUTHOR]

Novel biomass lignin/silica composites were prepared and isolated from rice husk renewable resources at different pHs. Selective precipitation was achieved by decreasing the solution pH from 9.5 to 1.5. When pH reached 3.5, the ratio of lignin and silica mostly achieved the maximum of 1:1. We selected lignin/silica composites as reactants to replace 20 wt% bisphenol A in preparing epoxy resin. The cured novel biomass function lignin/silica-based epoxy resin adhesive showed the highest adhesive strength up to 2.68 MPa, which displayed 123% of neat epoxy resin adhesive. In addition, lignin/silica composites were depolymerized through the hydrothermal method by NaOH as a catalyst, which was used as reactants to replace 35 wt% bisphenol A in the process of in situ synthesis of epoxy resin adhesive. At this point, the high epoxy value (1.42 wt%) and large adhesive strength (3.98 MPa) of lignin/silica-based epoxy resin adhesive were obtained, which adhesive strength was 183% of neat epoxy resin adhesive. The results demonstrated that depolymerized lignin/silica-based epoxy resin adhesive showed the higher epoxy value and the adhesive strength compared with neat epoxy resin adhesive and lignin/silica-based epoxy resin adhesive. Their function in epoxy matrix resulted in better processability. [ABSTRACT FROM AUTHOR]

Steam explosion lignin phenol formaldehyde (SEL–PF) adhesives were prepared by ternary gradual copolymerization. The parameters for the phenolate of steam explosion lignin (SEL) and preparation of SEL–PF adhesives were optimized. Under the optimum phenolate conditions, the phenolic hydroxyl content of lignin increased by 130%, whilst the methoxyl content was reduced by 68%. The SEL–PF adhesives were used to prepare plywoods by hot-pressing. The pH value, viscosity, solid content, free phenol content and free formaldehyde content of SEL–PF adhesives were investigated. The bonding strengths of the plywoods glued with SEL–PF adhesives were determined. The maximum SEL replacement percentage of phenol reached 70 wt%, and the properties of adhesives and plywoods met the Chinese National Standard (GB/T 14732-2006) for first grade plywood. [ABSTRACT FROM AUTHOR]

[Display omitted] • Convenient synthesis of multi-Si-void@SiO 2 @lignin-based carbon composites. • Stable construction of "high speed channel" formed by Li 4 SiO 4 and Li 2 O in SiO 2 layer. • Reserved space in the structure effectively responds to the volume change of Si. • Synergism of voids, Si, SiO 2 and lignin-based carbon realizes elxcellent properties. • High value utilization of lignin has environmental and economic benefits. As one of the most promising anode materials for high-performance lithium-ion batteries, the commercial application of Si faces many dilemmas. In this paper, a facile method is developed to substantially improve the cycling stability of Si-based anodes. Firstly, based on the Kirkendall effect, the Si nanoparticle was transformed into multi-Si-void@SiO 2 by heat-treatment. Then, the acid precipitation process was used to coat the lignin on the surface of the multi-Si-void@SiO 2 structure via the hydrogen-bond interaction, and after in-situ carbonization, multi-Si-void@SiO 2 @lignin-based carbon composite was formed. The optimum electrode material maintained the specific capacity of 759 mA h g−1 after 1300 cycles at the current density of 1.0 A/g. The great electrochemical performance is attributed to the four components of voids, Si, SiO 2 and lignin-based carbon (LC) performing their duties and synergistically, making the electrode exhibit excellent cycle stability. After long-term charge/discharge process, SiO 2 layer is fully activated to construct Li 4 SiO 4 and Li 2 O "high-speed channels", providing a "bridge" for Si to connect with the outside. And the reserved space inside the structure is conducive to the free expansion and contraction of Si. Meanwhile, lignin, as a cheap and renewable carbon source, greatly reduces the cost of material preparation. Consequently, the multi-Si-void@SiO 2 @LC composite presented here provides a feasible strategy for the large-scale development of highly stable Si-based anodes. [ABSTRACT FROM AUTHOR]