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In this work, a series of new lignin-graft copolymers were successfully prepared through enzymatic hydrolytic lignin (EHL)-initiated ring-opening alternating copolymerization of 3,4-dihydrocoumarin (DHC) and epoxides (EPO) through organocatalysis. A series of EPOs, including styrene oxide (SO), propylene oxide (PO), cyclohexane oxide (CHO) and lignin-derived-2-(2-methoxy-4-methyl-phenoxy) (MPO), together with DHC, were selected as model compounds to prepare EHL-g-P(DHC-alt-EPO), demonstrating the tailor-made potential of this synthetic protocol. The reaction conditions were optimized and the structures and thermal properties of EHL-g-P(DHC-alt-EPO) were fully elucidated by 1H, 13C and 31P NMR, FTIR spectroscopy, MALDI-TOF MS and GPC, DSC, and TGA. It was found that EHL-g-P(DHC-alt-SO) with a monomer conversion of 81.52%, DP of 3.21 and Mn of 62.9 kDa was prepared at a molar ratio of 5 : 5 : 1, 140 °C and 24 h. The UV shielding properties, antioxidant activity and biocompatibility of the as-prepared EHL-g-P(DHC-alt-EPO) was systematically evaluated. As a 'proof of concept' application, the potential of EHL-g-P(DHC-alt-SO) as an active ingredient in sunscreen was demonstrated, and a high sun protection factor (SPF) of 22.42 was achieved at 5 wt% dosage of EHL-g-P(DHC-alt-SO) in the cream, and the possible mechanism for the outstanding performance is also discussed. [ABSTRACT FROM AUTHOR]

Taking advantage of the structural characteristics of lignin-derived phenolic compounds, a combination of the Williamson and Tishchenko reactions produced a series of new α,ω-diene functionalized carboxylic ester monomers from both petrochemical and renewable resources, which were applicable in subsequent thiol–ene click and acyclic diene metathesis (ADMET) polymerizations, providing a series of poly(thioether esters) and unsaturated aromatic–aliphatic polyesters with high molecular weights. [ABSTRACT FROM AUTHOR]

Risk assessing newly synthesized chemicals prior to their applications is extremely important, if we want to ensure substitution of risky chemicals with more benign ones. During the past two decades, many analogs of bisphenol A (BPA) have been manufactured, while their toxicity remains less studied. The aim of this study was to compare the acute toxicity of a synthesized lignin-derived BPA (LD-BP) with that of BPA in representative aquatic organisms including two algal species ( Chlorella pyrenoidosa and Scenedesmus obliquus), a cladoceran species ( Daphnia magna), and the Japanese medaka ( Oryzias latipes). The results revealed that the two algal species showed different responses to the two chemicals. For C. pyrenoidosa, both BPA and LD-BP stimulated growth within 48 h of exposure, except for the 50 mg L of LD-BP treatment. After 96 and 144 h of exposures, BPA stimulated the growth of C. pyrenoidosa at low-exposure concentrations but inhibited its growth at high concentrations, while LD-BP caused a concentration-dependent response in C. pyrenoidosa. S. obliquus exhibited a monotonic concentration-response curve for both BPA and LD-BP exposures. For both D. magna and O. latipes, concentration-responses were monotonic with 96 h-LC of BPA and LD-BP of 11.7 and 5.0 mg L and 9.4 and 4.1 mg L, respectively. Our results demonstrate that LD-BP is more toxic than BPA in the representative aquatic organisms, and it can pose higher ecological risk to the aquatic ecosystem than BPA. [ABSTRACT FROM AUTHOR]

A bis(cyclic carbonate) was obtained via glycidylation of lignin-based bisphenol followed by cycloaddition with CO2. Further polyaddition between the bis(cyclic carbonate) and diamines led to the synthesis of polyurethanes. The structure and thermal properties of these polyurethane materials were elucidated by NMR, FT-IR, GPC, XRD, TGA and DSC. [ABSTRACT FROM AUTHOR]

Lignosulfonic acid, a byproduct of the paper industry, was demonstrated to be an efficient and green catalyst in water for the stoichiometric condensation of creosol with formaldehyde to synthesize lignin-derived renewable bisphenols. The distribution and structures of the products were confirmed by 1H NMR, 13C NMR, and FTIR spectroscopy and X-ray analysis; furthermore, a possible reaction mechanism was proposed. A polycarbonate was prepared from the bisphenol product and characterized as a model application, and thermogravimetric analysis (TGA) showed that decomposition occurred in a single stage with the maximum rate of degradation at approximately 420 °C. Differential scanning calorimetry (DSC) analysis showed that the glass transition temperature and melting peak of the polycarbonate were approximately 122 and 314 °C, respectively. The environmentally friendly characteristics of this study are featured by the integrated utilization of a biorenewable feedstock, a green biomacromolecule catalyst, and a green solvent for the preparation of valuable biochemicals and materials. [ABSTRACT FROM AUTHOR]

Soybean oil is beneficial to improve the compatibility between polylactide (PLA) and succinylated lignin (SAL), which leads to the preparation of a host of biobased composites containing PLA, SAL, and epoxidized soybean oil (ESO). The introduction of SAL and ESO enables the relatively homogeneous morphology and slightly better miscibility obtained from triply PLA/SAL/ESO composites after dynamic vulcanization compared with unmodified PLA. The rigidity of the composites is found to decline gradually due to the addition of flexible molecular chains. According to the reaction between SAL and ESO, the Tg of PLA/SAL/ESO composites is susceptible to the movement of flexible molecular chains. The rheological behaviors of PLA/SAL/ESO under different conditions, i.e., temperature and frequency, exhibit a competition between viscidity and elasticity. The thermal stability of the composites displays a slight decrease due to the degradation of SAL and then the deterioration of ESO. The elongation at break and notched impact strength of the composites with augmentation of ESO increase by 12% and 0.5 kJ/m2, respectively. The triply biobased PLA/SAL/ESO composite is thus deemed as a bio-renewable and environmentally friendly product that may find vast applications. [ABSTRACT FROM AUTHOR]

Lignin, a natural amorphous three-dimensional aromatic polymer, is investigated as an appropriate filler for biocomposites. The chemical modification of firsthand lignin is an effective pathway to accomplish acetoacetate functional groups replacing polar hydroxyl (–OH) groups, which capacitates lignin to possess better miscibility with poly(lactic acid) (PLA), compared with acidified lignin (Ac-lignin) and butyric lignin (By-lignin), for the sake of blending with poly(lactic acid) (PLA) to constitute a new biopolymer based composites. Generally speaking, the characterization of all PLA composites has been performed taking advantage of Fourier transform infrared (FTIR), scanning electron microscopy (SEM), dynamic Mechanical analysis (DMA), differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), rheological analysis, and tensile test. Visibly, it is significant to highlight that the existence of acetoacetate functional groups enhances the miscibility, interfacial compatibility, and interface interaction between acetoacetate lignin (At-lignin) and PLA. Identical conclusions were obtained in this study where PLA/At-lignin biocomposites furthest maintain the tensile strength of pure PLA. [ABSTRACT FROM AUTHOR]

The compact dimensional aggregate structure and the complex chemical components of lignocellulose go against its high value utilization. The mixture of dilute hydrochloric acid and n-butanol, which had a characteristic of homogeneous phase at high temperature and phase separation at low temperature, was proposed for lignocellulosic hydrolysis and hydrolysates separation. The results showed that lignocellulose was hydrolyzed under the synergy effect of hydrochloric acid and n-butanol in homogeneous condition, and hemicellulose and lignin hydrolysates were transferred automatically into dilute hydrochloric acid phase and n-butanol phase during the phase separation of the solvent after pretreatment, respectively. N-butanol accelerated lignin hydrolysis and protected β-O-4 linkage within lignin during the pretreatment. Meanwhile, the cellulose within solid phase product from the pretreatment was of high crystallinity, and its glucose yield in enzymatic saccharification at 48 and 72 h were 73.5% and 97.3%, respectively. This study provides a new method for lignocellulose hydrolysis and hydrolysates separation, and lays a theoretical foundation for lignocellulosic utilization of all component. [Display omitted] • Liquid-liquid phase-change solvent was proposed to pretreat lignocellulose. • Liquid-liquid phase-change solvent was biphase before and after pretreatment. • Liquid-liquid phase-change solvent was homogeneous during pretreatment. • Lignocellulose was hydrolyzed under the synergistic effect of acid and n-butanol. • Hemicellulose and lignin moved to dilute HCl and n-butanol phase, respectively. [ABSTRACT FROM AUTHOR]

One of the ultimate goals of green chemistry is to produce greener and more environmentally friendly chemicals to replace the existing toxic chemicals. In this study, Japanese medaka were exposed to 1.5 mg/L of bisphenol A or lignin-derived bisphenol for 60 days, and the expressions of various biochemical markers, effects on reproduction, and histopathology were evaluated. The results showed that concentrations of liver vitellogenin of LD-BP exposed males were approximately 125% higher compared to the control males. Total number of eggs from the BPA and LD-BP exposed fish was approximately 47% ( p < 0.001) and 25% ( p < 0.05) less than the control fish, respectively. Total number of brood was lower from the BPA (46%, p < 0.05) and LD-BP (17%, p < 0.05) exposed fish than that of the control fish. Relative to the control fish, catalase and glutathione- S -transferase were significantly affected by the two chemicals in all tested tissues. BPA and LD-BP caused lipid peroxidation in all the tested tissues. Furthermore, acetylcholinesterase and α-glucosidase activity were significantly inhibited. Histopathological analysis showed that both the testis and ovary were mildly damaged by both chemicals. LD-BP affected medaka slightly more severe than BPA except on the reproduction, which was most likely due to different uptake, translocation, binding to targets and metabolism. Our results demonstrated that chronic exposure to both chemicals caused several adverse effects to medaka. Further research on the toxicity of LD-BP to other aquatic organisms is needed before substitution of traditional BPA with LD-BP can be recommended. [ABSTRACT FROM AUTHOR]

One of the most attractive routes to valorize lignin is to prepare lignin-based materials which can be used as high-value products, such as dye absorbents. Various processes have been investigated to improve the properties of lignin. In this study, a hypervalent iodine reagent (III) was employed to achieve oxidative coupling of Kraft lignin (KL). The structural changes were investigated by FTIR, quantitative 31P NMR, 2D-HSQC, and GPC. Oxidative coupling between lignin aromatic C(sp2) H bonds and aromatic C(sp2)-H functionalization with aliphatic hydroxyl group occurred via inter- or intramolecular modes, with resultant decreases of the aromatic protons and hydroxyl groups. In addition, selective modification of aliphatic OH groups in β-O-4′ linkages occurred leading to the formation of aromatic carbonyl groups. Increases in molecular weights with the appearance of conjugated C O groups were also observed. The oxidative crosslinked lignin (KL-2.0) exhibited better adsorptive features for brilliant green (251.2 mg/g) than that of unmodified KL (59.4 mg/g). Their adsorption kinetics were investigated by pseudo-first-order, pseudo-second-order and mixed-order models. Furthermore, the Langmuir and Freundlich models were employed to study the adsorption isotherms. Oxidative coupling of Kraft lignin between lignin C(sp2) H bonds and aromatic C(sp2) H functionalization with aliphatic hydroxyl groups was achieved by employing hypervalent iodine reagent (III), resulting an new oxidative cross-linked lignin with better adsorptive features for brilliant green (251.2 mg/g) than that of unmodified KL (59.4 mg/g). [Display omitted] • New oxidative coupling of lignin with high selectivity was achieved in the presence of hypervalent iodine reagent (PIFA). • The treatment of KL with PIFA appeared to selectively oxidize hydroxyl group in β-O-4′ linkages into carbonyl group. • The adsorption capacity of lignin for brilliant green has been significantly improved after oxidative coupling modification. [ABSTRACT FROM AUTHOR]

This study pioneers an integrated approach to convert carbohydrates and lignin in corn stover into microbial lipids and advanced energy carbon nanofibers for supercapacitors using ionic liquid-based organic electrolyte ([Emim][OAc]/DMSO (X ILs = 0.2, X ILs is the molar fraction of ionic liquids in the electrolyte). • Dissolution pretreatment of Corn stover was performed by ionic liquids-based eletrolytes. • Ionic liquids-based eletrolytes acted as solvent for corn stover pretreatment and lignin electrospinning. • Carbohydrates in corn stover were converted into microbial lipids by R. toruloides Y4. • Lignin in corn stover was converted to nano carbon fibers as energetic materials for supercapacitors. Full utilization of the entire components of lignocellulosic biomass is one of the challenges in modern biorefinery via integrated approaches. This study pioneers an integrated approach to convert carbohydrates and lignin from corn stover into microbial lipids and advanced energy carbon nanofibers for supercapacitors using ionic liquid-based organic electrolyte ([Emim][OAc]/DMSO (X ILs = 0.2, X ILs is the molar fraction of ILs in the electrolyte). The pretreated corn stover was delignified by 60 wt%, and its saccharification was enhanced from 0.11 g.g−1 total reducing sugar (TRS) and 0.08 g.g−1 glucose to 0.68 g.g−1 TRS and 0.43 g.g−1 glucose yields within 12 h by enzymatic hydrolysis. The hydrolysates were used as carbon sources for cultivating R. toruloides Y4 for lipid production, yielding 13.8 g/L biomass and 51.0 % lipid. The lignin after enzymatic saccharification was integrated with extracted lignin to form a lignin organic electrolyte solution, which was directly prepared into electrospun nanofibers combined with polyacrylonitrile that served as electrode materials for supercapacitors with good performance. [ABSTRACT FROM AUTHOR]