Materials
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2018
·Vol. 11
·期 9
·1505
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IF 2.467
Yan Song,Xu Zong,Nan Wang,Ning Yan,Xueying Shan,Jinchun Li
Lignin can be a candidate as a charring agent applied in halogen-free flame retardant polymers, and incorporation of silicon and nitrogen elements in lignin can benefit to enhancing its thermal stability and charring ability. In the present work, wheat straw alkali lignin (Lig) was modified to incorporate silicon and nitrogen elements by γ-divinyl-3-aminopropyltriethoxysilane, and the modified lignin (CLig) was combined with ammonium polyphosphate (APP) as intumescent flame retardant to be applied in poly(Lactic acid) (PLA). The flame retardancy, combustion behavior and thermal stability of PLA composites were studied by the limited oxygen index (LOI), vertical burning testing (UL-94), cone calorimetry testing (CCT) and thermogravimetric analysis (TGA), respectively. The results showed a significant synergistic effect between CLig and APP in flame retarded PLA (PLA/APP/CLig) occured, and the PLA/APP/CLig had better flame retardancy. CCT data analysis revealed that CLig and APP largely reduced the peak heat release rate (PHRR) and total heat release rate (THR) of PLA, indicating their effectiveness in decreasing the combustion of PLA. TGA results exhibited that APP and CLig improved the thermal stability of PLA at high temperature. The analysis of morphology and structure of residual char indicated that a continuous, compact and intumescent char layer on the material surface formed during firing, and had higher graphitization degree. Mechanical properties data showed that PLA/APP/CLig had higher tensile strength as well as elongation at break.Keywords:wheat straw soda lignin;silicon and nitrogen elements;poly(lactic acid);thermal stability;combustion behavior
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ACS Omega
·
2018
·
IF 0
Gaofeng Zhao,Haiyue Ni,Lina Jia,Shixue Ren,Guizhen Fang
Blends of alkali lignin and acrylonitrile–butadiene–styrene (ABS) resin are physically mixed and injected into the injection molding system. Although the components of the blend are bound together by intermolecular forces, noticeable phase separation still occurs. In the present study, inverse gas chromatography technology was used to characterize the Hansen solubility parameters of alkali lignin/ABS blends. The relationship between the Hansen solubility parameters and thermodynamic properties was then determined. Hansen solubility parameters, at room temperature, of alkali lignin/ABS blends containing 0, 10, 20, and 30 wt % alkali lignin were 17.40, 19.20, 18.98, and 17.37 (J/cm3)0.5, respectively. Hansen solubility parameters of the blends were shown, both experimentally and theoretically, to be related to their mechanical and thermal properties.
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Molecular Catalysis
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2018
·
IF 0
Jiang Li,Hui Sun,Jia-xing Liu,Jun-jie Zhang,Zhen-xing Li,Yao Fu
Lignin has recently attracted much attention as a promising resource to produce fuels and aromatic chemicals. The selective cleavage of C O bond while preserving the aromatic nature has become one of the major challenges in the catalytic valorization of lignin to aromatic chemicals. In this work, we report that the selective reductive cleavage of C O bond in lignin model compounds can be successfully achieved through heterogeneous iron catalysis. The hydrogenolysis of α-O-4 model linkage shows that the iron catalyst prepared by the simultaneous pyrolysis of iron acetate and 1,10-phenanthroline on activated carbon at 800 °C is the most active iron catalyst, affording phenol and toluene with yields of 95% and 90%, respectively. This aromatics selectivity is found to be much higher than that obtained over noble metal catalysts. The presence of N⋯Fe species as the active center of heterogeneous iron catalyst was confirmed by various technologies especially XPS and H 2 -TPR. For the β-O-4 model linkage, the vicinal OH group was essential for the iron-catalyzed hydrogenolysis of ether linkage. The oxidation of the α-carbon in the β-O-4 model compounds can significantly decrease the bond dissociation energy of ether linkage, giving depolymerization products in moderate to excellent yields.
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COMPOSITES SCIENCE AND TECHNOLOGY
·
2018
·
IF 5.16
Wei Wu,Haibing He,Tao Liu,Ruichao Wei,Xianwu Cao,Qijun Sun,Shishir Venkatesh,Richard K.K. Yuen,Vellaisamy A.L. Roy,Robert K.Y. Li
Lignin can be employed as a sustainable functional additive and reinforcement filler for polymers. In this work, melamine phosphate modified lignin (MAP-lignin) was synthesized as a bio-based halogen-free flame-retardant agent. The synergetic effects between MAP-lignin and rice husk ash (RHA) on the thermal stability, dynamic mechanical performance and flame-retardant properties of the poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) biocomposites were investigated. The results revealed that MAP-lignin and RHA could significantly increase the char residue and MAP-lignin had a good miscibility with P34HB. The incorporation of MAP-lignin and RHA as stiff fillers could enhance the storage modulus of the P34HB matrix. Moreover, the tensile strength and elongation at break of the P34HB/RHA composite could be improved due to the MAP-lignin could serve as a compatibilizer to improve the interaction between RHA and P34HB. Cone calorimetry data demonstrated that the addition of 30 wt% MAP-lignin and 5 wt% RHA reduced the peak heat release rate ( PHRR ) and total heat release ( THR ) of P34HB noticeably by 42.8 and 24.3%, respectively. In addition, the CO 2 production rate and CO concentration could be significantly suppressed by the addition of MAP-lignin. The enhanced flame retardancy of P34HB composite should be ascribed to the barrier effect of the increased char residue with compact and intact structure, as well as the released gases from the decomposition of melamine.
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高影响因子
FUEL PROCESSING TECHNOLOGY
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2018
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IF 3.956
Huamei Yang,Koyo Norinaga,Ji Li,Wenyou Zhu,Haijun Wang
This study aimed to experimentally investigate the effect of HZSM-5 on the distribution of volatile products, especially carbon monoxide (CO), C 1 –C 5 hydrocarbons and aromatic hydrocarbons (AHs) during catalytic pyrolysis of lignin and lignin model compounds. Catechol was pyrolyzed using a two-stage tubular reactor (TS-TR) connected to a gas chromatography system over HZSM-5 at 550–950 °C. Forty-three products, including four inorganic gases, twenty C 1 –C 5 hydrocarbons, and nine AHs were quantified using three GC-columns. Results indicated that HZSM-5 accelerated the catechol conversion with a large amount of CO and AHs produced. C 1 –C 5 hydrocarbons were formed during non-catalytic pyrolysis of model compounds, and consumed quickly during HZSM-5 catalytic pyrolysis of catechol. Catalytic pyrolysis of phenol , guaiacol and syringol was carried out at 650 °C in the TS-TR over HZSM-5. HZSM-5 obviously promoted the conversion of lignin model compounds, and largely increased the yield of volatile products especially CO and AHs. Three lignin samples were also catalytically pyrolyzed over HZSM-5 in the TS-TR at 650 °C. HZSM-5 increased the yield of C 2 -C 3 hydrocarbons and AHs, and reduced the yield of oxygenated compounds. HZSM-5 could promote the formation of AHs (lower than 10 wt%) during lignin pyrolysis, but not as obviously as during model compounds pyrolysis (higher than 19 wt%). High yields of char and tar would account for the low catalytic efficiency of HZSM-5 during lignin pyrolysis.
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高影响因子
MOLECULES
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2019
·Vol. 24
·期 9
·1834
·
IF 3.06
Feifei Wu,Xin Jia,Lijun Yin,Yongqiang Cheng,Yuxin Miao,Xiuqing Zhang
Lentinus edodes, whose polysaccharides possess diverse bioactivities, commonly grows on hardwood sawdust composed of hemicellulose, lignin and cellulose. In this study the effect of hemicellulose and lignin on the growth of mycelia, as well as the physicochemical properties of polysaccharides fromL. edodesmycelia (LEPs) were investigated. The antioxidant properties of LEPs were evaluated through radical scavenging assays in vitro and through theCaenorhabditis elegansmodel in vivo. The results showed that hemicellulose at a concentration of 4% increased the yield of the mycelia biomass to twice that of the control group. Meanwhile, when cultured with 4.0% hemicellulose, the polysaccharide content of the mycelia was raised by 112.2%. In addition, the appropriate concentration of lignin could stimulate mycelia growth and polysaccharide biosynthesis inL. edodes. Monosaccharide composition analysis showed that a higher content of xylose was found when mycelia were cultured with higher concentrations of hemicellulose. The molecular structure, including the molecular weight distribution and configuration type, was affected by hemicellulose and lignin. Antioxidant assays indicated that LEPs supplemented with hemicellulose and/or lignin possessed higher radical scavenging abilities in vitro and exhibited a thermal resistance effect onC. elegans, implying that the antioxidant effect is potent in vivo. In summary, the addition of hemicellulose and lignin improved the biosynthesis and bioactivity of LEPs.Keywords:Lentinus edodes;polysaccharide;hemicellulose;lignin;antioxidant activity;Caenorhabditis elegans
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2019
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IF 3.571
Mingsong Zhou,Dongping Wang,Ruifen Peng,Dongjie Yang,Xueqing Qiu,Yong Qian
4-Amion-2,2,6,6-tetramethylpiperidine (Temp) was grafted into sodium lignosulfonate (SL) to obtain hindered amine-modified lignosulfonate (SL–Temp). Then, the polymer surfactant (SL–Temp–CTAB) was prepared using cetyltrimethylammonium bromide (CTAB) and SL–Temp. Obtained SL–Temp–CTAB was used as an emulsifier to prepare a green emulsifiable concentrate (EC) of avermectin (AVM), which shows good emulsifying property and storage stability. The prepared AVM green EC can form AVM-loaded microspheres with nanometer particle size distribution after emulsification in water. After ultraviolet irradiation for 70 h, the AVM retention rate of the green EC prepared using SL–Temp–CTAB was 75.8%, which is much higher than that of commercial EC (0.4%) and the green EC prepared using unmodified SL (31.4%). Moreover, the AVM green EC prepared using SL–Temp–CTAB has slow-release performance, and the release equilibrium time is 5.3 times the commercial EC. Therefore, the newly prepared AVM green EC using a lignin-based functional emulsifier shows good antiphotolysis and slow-release performance compared to the traditional EC.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2017
·
IF 3.671
Dezhan Ye,Jinfeng Kong,Shaojin Gu,Yingshan Zhou,Caoxing Huang,Weilin Xu,Xi Zhang
Even with outstanding radical capturing ability, the utilization of lignin as a natural antioxidant in polypropylene (PP) still has been pended. Usually, the compatibility of its blends is improved based on the reaction of hydroxyl content, thus leading to the decreasing content of phenolic hydroxyl (Ph-OH) group and inferior thermal-oxidative stability of lignin blends. Here, the selective aminolysis of acetylated Kraft lignin (pyr-KL) was investigated, which structures were characterized using FTIR, 31 P-NMR and GPC. The Ph-OH group of acetylated KL could be released by the addition of pyrrolidine; however the aliphatic hydroxyl group is still blocked. With the control of reaction conditions, the highest oxidation induction time of pyr-KL/PP (0.5 wt% loading) reaches up to 22.6 min, almost 2.6 times than that of pure PP. More importantly, the mechanical properties of PP were also maintained under the loading of pyr-KL, which is much better than that of curde KL/PP.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2017
·
IF 3.671
Kai Chen,Dezhan Ye,Shaojin Gu,Yingshan Zhou
Which factors are crucial to improving lignin antioxidant ability in polymers has been debated over years. Here, the structural effect of natural antioxidant from technical Kraft lignin (KL) on the oxidation induction time (OIT) of KL/polypropylene (PP) was quantitatively investigated using correlation analysis model instead of traditional linear fitting model. The correlation coefficient and significance value of their relationship clearly demonstrated the dominating role of non-condensed Phenolic OH (Ph-OH) in improving KL/PP thermal-oxidation stability, subsequently followed by M ¯ n , aliphatic OH/total Ph-OH, condensed Ph-OH and polydispersity. OIT is positive with non-condensed and total Ph-OH, while it declines with increase of the above other factors. Remarkably, the longest OIT (∼90 min) was obtained even at extreme loading (0.5 wt%), almost ∼911% and ∼201% huge increase in contrast to that of pure PP and crude KL/PP composite, respectively. Meanwhile, the mechanical properties of KL fractions/PP blends can be maintained at the same or better level than that of pure PP, due to strong interfacial adhesion strength.
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DESALINATION
·
2024
·
IF 8.3
Jinsong He,Wenjie Liu,Fan Ni,Dong Tian,Yongjia Lei,Jianmei Zou,Yanzong Zhang,Fei Shen,Xiaochan An
Sacrificed template strategy has become a promising pathway to construct high performance loose nanofiltration (LNF) membranes for dye-containing wastewater treatment. However, few studies have been conducted on the recycling of templates in the LNF membrane preparation. In this study, lignin nanoparticles (LNPs) with abundant biomass sources, low cost, renewable ability, were attempted to be used as a recycled sacrificed template for the first time. The LNPs were easily renewed by concentration and NaOH dialysis with smaller nano-size and more hydrophilic surface. The optimized P-LNF-50 membrane prepared by pristine LNPs templates exhibited high water permeability of 146.24 LMH·bar −1 , excellent separation of dye/salt (i.e. rejection: 97.79 % for CR, 0.48 % for Na 2 SO 4 , 0.25 % for NaCl), and superior long-term stability. Interestingly, the R1-LNF-70 membrane prepared by 1 st recycled LNPs templates can still maintain high water permeability of 132.97 LMH·bar −1 and excellent separation of dye/salt (i.e. rejection rate: 98.31 % for CR, and 1.27 % for Na 2 SO 4 ). While the 2 nd recycled LNPs can not produce satisfied LNF membranes due to its poor figuration and easy aggregation. The inherent relationships between LNPs templates and selective layers were deeply explored. Importantly, the Sankey chart of recycling LNPs template technique and cost analysis indicated that the LNPs could be used as green templates for two cycles with comparable permeability and selectivity of dye/salts. Overall, our study paves the way for recycling of sacrificed templates for the scalable fabrication of high performance LNF membranes.
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Ruoteng Ma,Chao Duan,Chenyue Yan,Kang Yang,Qi Fan,Xiaorang Nie,Lei Dai,Yonghao Ni
Most of the bio-based hydrogels tend to malfunction under a high-temperature condition, as the crosslinked network structure readily disintegrates, failing to meet the demands of hot environment. Herein, we exploit a thermostable composite hydrogel (CH) mainly using bio-based hyperbranched lignin nanoparticles (H-LNPs), TEMPO-oxidized cellulose nanofibers (TOCN), and scleroglucan (Slg), followed by a slow evaporation to form a multifunctional CH film. Thanks to the uniform distribution of H-LNPs and TOCN, which are rich in hydroxyl groups, within the hydrogel matrix, the crosslinking density, storage modulus, loss modulus, and thermal stability of the CHs are remarkably enhanced. As a result, the optimum CH demonstrates excellent thermal resistance and structural stability even after 196 h at 140 °C. Moreover, the resultant CH film exhibits outstanding UV shielding (>99.8 %) and solar radiation shielding (cooling 6.6 °C), endowing it as an ideal candidate for thermal insulation. These findings underscore the potential of H-LNPs in the development of robust, thermostable, and thermally insulating hydrogels for industrial applications in extreme environments.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Xinxin Zhang,Gang Li,Chen Chen,Hongxian Fan,Jing Fang,Xingjiang Wu,Junjie Qi,Hao Li
This study aims to develop a chitosan/polyvinyl alcohol (CS/PVA) composite film (QZCS/PVA) for food packaging, enhanced by the incorporation of quaternary ammonium lignin/ZnO nanoparticles (QAL/ZnO) to improve its antibacterial, antioxidant, and mechanical properties. The QAL/ZnO nanoparticles were synthesized using a co-precipitation method, resulting in a synergistic effect that enhances the uniformity and stability of the composite film. The double cross-linked CS/PVA composite film containing QAL/ZnO nanoparticles effectively mitigates the brittleness of pure chitosan films, achieving a tensile strength of 95.89 MPa. Crucially, the inclusion of QAL/ZnO imparts exceptional antioxidant and antibacterial properties to the QZCS/PVA composite film. Disk diffusion assays revealed markedly enhanced antibacterial efficacy against Staphylococcus aureus and Escherichia coli in comparison to analogous biopolymer films. The dense network structure of the composite film also provides excellent water resistance, which contributes to extending the shelf life of food products. In a 12-day grape preservation experiment, the composite film exhibited outstanding preservation performance. These results underscore the potential of the CS/PVA composite film containing lignin and chitosan for food packaging applications, offering significant advantages in improving food preservation.
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