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Commonly, lignin macromolecules have limitations in application to the thermoplastics industries due to poor dispersibility and interfacial compatibility within ligno-bioplastics. In this study, the dispersibility and interfacial compatibility of ethanol organosolv lignin (EOL) in PLA-based ligno-bioplastic were improved by enhancing the thermoplasticity via oxypropylation. Further, three types of EOLs extracted from different severity conditions were applied to investigate the effect of the structural characteristics of EOLs on the changes in the thermal properties. The thermal properties of oxypropylated EOL were dependent on the structural characteristics of the initial EOL as well as the degree of polymerization of propylene oxide. The thermoplasticity of EOLs extracted under mild condition was effectively increased as a new T g and melting were observed. Based on increased thermoplasticity, the dispersibility and interfacial compatibility of EOL within PLA-based ligno-bioplastic were successfully improved, which compensates for the deterioration in mechanical strength of ligno-bioplastic due to the addition of unmodified EOL. Therefore, oxypropylation of EOL with suitable structural characteristics promises improved availability as a thermoplastic material. [Display omitted] • The oxypropylation of three types of EOL was conducted. • Oxypropylated of LL and ML was enhanced thermoplasticity with a new T g. • Enhanced thermoplasticity of EOL contributed to the compatibility with PLA. • Mechanical strength of ligno-bioplastic was supplemented by oxypropylation of EOL. • The properties of oxypropylated EOL was affected by characteristics of initial EOL. [ABSTRACT FROM AUTHOR]

The intricate structure of lignin, characterized by a mix of hydrophilic components and hydrophobic structures from its aliphatic and aromatic constituents, poses challenges in creating monodisperse particles. This is due to the need for precise modulation of self-assembly kinetics. Herein, we explore a correlation between the substructure of lignin and its capacity for self-assembly. We have conducted an in-depth investigation into the interactions between hydrophilic groups, such as phenolic and aromatic-OH, and monolignols with interunit linkages that are involved in the formation of lignin particles (LPs). A high degree of hydrophilicity with a condensed structure is crucial for high supersaturation levels, which in turn determines the growth phase and leads to small LPs. An approach based on tailoring the supersaturation level which is contingent on the structural characteristics of extracted organosolv lignin was used to obtain remarkably uniform LPs with mean diameters of approximately 230 and 480 nm. The results of this study have the potential to serve as a foundation for the preparation of monodisperse LPs derived from various lignin sources as well as for the development of methods to extract lignin containing a specific chemical substructure. [Display omitted] • Understanding the hydro/lipophilic balance in LPs guides self-assembly kinetics. • The average Mw of lignin did not exert a major effect on LPs size. • Higher hydrophilicity with condensed structures in lignin yields small LPs. • Tailored supersaturation based on lignin substructure yielded uniformly sized LPs. • LPs size was regulated by adjusting the level of nuclei supersaturation. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the degradation characteristics of kraft lignin (KL) during peracetic acid (PAA) treatment, and to produce potentially valuable polymers of low molecular weight lignin by controlling the reaction conditions. For the peracetic acid treatment, acetic acid (AA) and hydrogen peroxide (HP) were directly mixed at ratios of 4:1, 1:1, and 1:4 (v/v) and employed as reaction media. After PAA treatment of kraft lignin at 80 °C, complete dissolution of the lignin and reduction in the molecular weight were observed. When the PAA reaction was performed at high HP concentration (1:4, v/v), the aromatic lignin skeleton opened and converted to a structure containing large amounts of carboxyl groups. On the other hand, the treatment at high AA concentration (4:1, v/v) decomposed lignin while maintaining its aromatic structure. Hence, we demonstrated that the selective production of lignin-derived polymers can be controlled depending on PAA and HP concentrations. Unlabelled Image [ABSTRACT FROM AUTHOR]

Abstract The main purpose of this study was simultaneous production of glucose, ethanol organosolv lignin (EOL), and furfural for total utilization of lignocellulosic biomass to improve economics of biorefinery. The glucose production (37.1 g, under conditions of 160 °C with 1% sulfuric acid) was significantly increased after organosolv pretreatment, dissolving 11.4 g of the initial hemicellulose-derived sugars and 22.6 g of the initial lignin. Progressively, organosolv lignin precipitation and furfural production processes were conducted using the liquid hydrolysates obtained after organosolv pretreatment. 12 g of EOL (at 160 °C, 1% sulfuric acid) was yielded with the remaining residues of soluble lignin-derived compounds in the liquid hydrolysates. Also, 7.9 g of furfural (at 160 °C, 1% sulfuric acid) was observed after additional acid-catalyzed treatment from the liquid hydrolysates. Consequently, a high yield of glucose, EOL and furfural can be obtained simultaneously using ethanol organosolv pretreatment. Highlights • Ethanol organosolv pretreatment was conducted for total utilization of biomass. • Biomass components were separated after ethanol organosolv pretreatment. • 37.1 g of glucose was produced after enzymatic hydrolysis. • 12.0 g of EOL and 7.9 g of furfural were obtained by additional process. • This concept of process was proposed for the competitiveness of biorefinery. [ABSTRACT FROM AUTHOR]

• Antioxidant activity of ethanol organosolv lignin and synergy were investigated. • Phenolic-OH content was predominant factor in the antioxidant activity of the lignin. • Lignin with a higher phenolic-OH and a lower IC50 value covered wide synergy ranges. • Synergy with myricetin was verified by comparing predicted and actual values. • Phenolic-OH ratio of myricetin and the lignin for the synergy was suggested. Lignin has potential as a substitute for natural antioxidants in cosmetics and food industries due to its radical scavenging ability and price competitiveness. The antioxidant activity of lignin depends on its structural properties, and they accordingly have synergy with natural antioxidants. Based on the structural characteristics, the antioxidant activity of ethanol organosolv lignin (EOL) and synergy with myricetin were investigated. The phenolic-OH content was a predominant factor in the antioxidant activity of EOL, and EOL-H with a higher phenolic-OH content and lower IC 50 value (0.17 mg/mL) covered a wide synergy range of 1:32–2:1 (EOL:myricetin). The synergistic effect was verified by comparing predicted and actual values based on ESR analysis, and the phenolic-OH ratio (>0.4) of myricetin and EOL for the synergy was suggested. In this respect, the results highlight the potential of lignin with high phenolic-OH content as a substitute for commercial antioxidants with superior activity and broad synergy ranges. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the color and chemical changes of natural wood veneers after ultraviolet (UV) exposure for automotive interior materials. To control the photodegradation, chemical treatments with hydrogen peroxide (H2O2) and sodium hypochlorite (NaClO) solution were applied to the veneer under different concentration conditions. The veneers treated with H2O2 showed strong color changes on the surface after the UV test. On the other hand, the veneers treated with NaClO solution (2-3% concentration) showed excellent color stability compared to the untreated veneer because NaClO partially removed lignin compounds on the veneer surface. NaClO can improve the color stability by destroying the lignin structures. However, 3% NaClO condition was seen to cause surface damage although this treatment condition had the best effect on photoprotection. Therefore, treatment with 2% NaClO was the best condition in this study for against color change and photodegradation caused by UV light. [ABSTRACT FROM AUTHOR]

Lignin has different structural characteristics depending on the extraction conditions. In this study, three types of ethanol organosolv lignin (EOL) were produced under different extraction conditions involving the reaction temperature (140, 160, 180 °C), sulfuric acid concentration (0.5, 1, 1.5 %), and ethanol concentration (40, 60, 80 %) to compare the difference in properties when mixed with polylactic acid (PLA) matrix after atom transfer radical polymerization (ATRP). ATRP of EOL was conducted to improve its compatibility with PLA using methyl methacrylate (MMA) as a monomer. The molecular weight of each EOL increased significantly, and the glass transition temperature (T g) decreased from approximately 150 to 110 °C. The EOL- g -PMMA copolymer exhibited a melting point (T m), whereas EOL did not, implying that the thermoplasticity increased. The EOL- g -PMMA/PLA blend and film were prepared with 10 % of the copolymer in the PLA matrix. The tensile strength and strain of the blend were higher than those of unmodified organosolv lignin as the compatibility increased, and the UV transmittance was lower than that of neat PLA because of the UV protecting properties of EOL moiety. • The ATRP using three EOL types was successfully conducted. • The T m appeared after the ATRP. • Compared to the neat EOL/PLA blend, the EOL- g -PMMA/PLA blend showed similar mechanical strength to the neat PLA. • EOL- g -PMMA showed UV protection properties in the PLA matrix. [ABSTRACT FROM AUTHOR]

• A sequential process was proposed for total utilization of woody biomass. • Hemicellulose was selectively decomposed with producing xylooligomers. • Lignin was degraded by 50% diluted PAA treatment with producing dicarboxylic acids. • Cellulose accessibility to the enzyme was improved by constituent deconstruction. For improving the economic efficiency of the biorefining concept, selective decomposition and separation of biomass components is indispensable. In this respect, a sequential pretreatment process consisting of liquid hot water treatment and diluted peracetic acid (PAA) treatment was proposed for total utilization of lignocellulosic woody biomass. During the liquid hot water treatment, hemicellulose can be decomposed efficiently without significant loss of cellulose and lignin, implying the possibility for xylooligomer production by thermochemical treatment. In the PAA treatment, lignin was successfully degraded and liquefied using a 50% diluted PAA solvent, suggesting the possibility of dicarboxylic acid production. After the sequential process proposed in this study, the cellulose accessibility to the enzyme could be maximized by inducing selective deconstruction of hemicellulose and lignin. [ABSTRACT FROM AUTHOR]

Acetylated lignin (AL) can improve compatibility with commercial plastic polymers compared to existing lignin and can be used as an effective additive for eco-friendly biocomposites. For this reason, AL can be effectively incorporated into polylactic acid (PLA)-based biocomposites, but its biodegradation properties have not been investigated. In this study, biodegradation experiments were performed under mesophilic and thermophilic conditions to determine the effect of AL addition on the biodegradation characteristics of PLA-based biocomposites. As a result, the PLA-based biocomposite showed a faster biodegradation rate in a thermophilic composting environment, which is higher than the glass transition temperature of PLA, compared to a mesophilic environment. 16S rDNA sequencing results showed that differences in microbial communities depending on mesophilic and thermophilic environments strongly affected the biodegradation rate of lignin/PLA biocomposites. Importantly, the addition of AL can effectively delay the thermophilic biodegradation of PLA biocomposites. As a result of tracking the changes in physicochemical properties according to the biodegradation period in a thermophilic composting environment, the main biodegradation mechanism of AL/PLA biocomposite hydrolysis. It proceeded with cleavage of the PLA molecular chain, preferential biodegradation of the amorphous region, and additional biodegradation of the crystalline region. Above all, adding AL can be proposed as an effective additive because it can minimize the decline in the mechanical properties of PLA and delay the biodegradation rate more effectively compared to existing kraft lignin (KL). [ABSTRACT FROM AUTHOR]

A technology to extract lignin oil from pretreated biomass has been developed for a cosmetic additive application (i.e., UV protection) through isopropyl alcohol without any catalyst. It was used for co-product lignin oil with XOS from a biorefinery process in this study. One of the key factors impacting economic feasibility is extraction solvent recovery, and it is important to design the process details based on techno-economic analysis. Therefore, this study has integrated lab experiments, process designs with Aspen Plus process simulations, and Excel-based techno-economic analysis to investigate the effect of solvent recovery on overall economics. Three options for solvent recovery (e.g., distillation, salting-out, and molecular sieve) have been explored. The salting-out method showed the best economic performance with an IRR of 33.6%, while the distillation method was 21.7% and the molecular sieve method was 16.7%. Key parameters are also identified by sensitivity analyses, which indicate the improvement potential for each case. This study has laid a foundation for lignin oil production studies, but its concept and approach can be applied to any solvent recycling in a biorefinery process, which is often neglected in lab-scale biorefinery studies. [Display omitted] [ABSTRACT FROM AUTHOR]