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Valorization of Tree Bark-Derived Suberin in Applications for the Bio-Based Composites Industry–A Recent Review
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作者 Aleksandra Jeżo 《Journal of Renewable Materials》 EI CAS 2024年第6期1029-1042,共14页
Bark extracts are sustainable sources of biopolymers and hold great promise for replacing fossil fuel-based polymers,for example,in wood-based composites.In addition to primary and secondary metabolites,tree bark also... Bark extracts are sustainable sources of biopolymers and hold great promise for replacing fossil fuel-based polymers,for example,in wood-based composites.In addition to primary and secondary metabolites,tree bark also contains suberin,which plays a major role in protecting the tree from environmental conditions.Suberin is a natural aliphatic-aromatic cross-linked polyester present in the cell walls of both normal and damaged external tissues,the main component of which are long-chain aliphatic acids.Its main role as a plant ingredient is to protect against microbiological factors and water loss.One of the most important suberin monomers are suberin fatty acids,known for their hydrophobic and barrier properties.Therefore,due to the diverse chemical composition of suberin,it is an attractive alternative to hydrocarbon-based materials.Although its potential is recognized,it is not widely used in biocomposites technology,including wood-based composites and the polymer industry.The article will discuss the current knowledge about the potential of suberin and its components in biocomposites technology,which will include surface finishes,composite adhesives and polymer blends. 展开更多
关键词 SUBERIN suberinic acids wood composites BIOcompositeS biopolyester
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Preparation and Drug-Release Property of Polycaprolactone (PCL)/Polyglycolic Acid (PGA) Composite Masterbatch with Drug of Tea Polyphenols (TPs)
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作者 吴改红 刘淑强 +6 位作者 杨雅茹 莫易涵 李杰特 李静静 张菂 杨智超 陆东东 《Journal of Donghua University(English Edition)》 CAS 2023年第3期277-283,共7页
In order to effectively control the drug-release rate of medical textiles,biodegradable polycaprolactone(PCL) and polyglycolic acid(PGA) were blended at various mass ratios to prepare composite masterbatches for medic... In order to effectively control the drug-release rate of medical textiles,biodegradable polycaprolactone(PCL) and polyglycolic acid(PGA) were blended at various mass ratios to prepare composite masterbatches for medical textiles.The surface morphology and the chemical structure of the masterbatches were analyzed.The crystallization,mass losses,strengths and drug-release rates of the composite masterbatches at different PCL/PGA mass ratios were explored.The results show that the degradation rate of the PGA carrier is obvious higher than that of the PCL carrier,and PCL,PGA and the tea polyphenol(TP) drug just physically mix without chemical reaction.During the degradation,the strength of the composite masterbatches gradually decreases.In addition,the drug-release rates of composite masterbatches at different mass ratios are different,and the more the PGA in the composite masterbatches,the faster the drug release of the composite masterbatches.The drug-release rate of the composite masterbatches can be controlled by adjusting the contents of PCL and PGA. 展开更多
关键词 polycaprolactone(PCL) polyglycolic acid(PGA) tea polyphenol(TP) composite masterbatch drug release
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Photocatalytic activity and kinetics for acid yellow degradation over surface composites of TiO_2-coated activated carbon under different photocatalytic conditions 被引量:3
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作者 曾孟雄 李佑稷 +2 位作者 马明远 陈伟 李雷勇 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第4期1019-1027,共9页
TiO2-coated activated carbon surface (TAs) composites were prepared by a sol-gel method with supercritical pretreatment. The photocatalytic degradation of acid yellow (AY) was investigated under UV radiation to es... TiO2-coated activated carbon surface (TAs) composites were prepared by a sol-gel method with supercritical pretreatment. The photocatalytic degradation of acid yellow (AY) was investigated under UV radiation to estimate activity of catalysts and determine the kinetics. And the effects of parameters including the initial concentration of AY, light intensity and TiO2 content in catalysts were examined. The results indicate that TAs has a higher efficiency in decomposition of AY than P25, pure TiO2 particles as well as the mixture of TiO2 powder and active carbon. The photocatalytic degradation rate is found to follow the pseudo-first order kinetics with respect to the AY concentration. The new kinetic model fairly resembles the classic Langmuir-Hinshelwood equation, and the rate constant is proportional to the square root of the light intensity in a wide range. However, its absorption performance depends on the surface areas of catalysts. The model fits quite well with the experimental data and elucidates phenomena about the effects of the TiO2 content in TAs on the degradation rate. 展开更多
关键词 PHOTOCATALYSIS TiO2-coated activated carbon acid yellow composite catalyst
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The effect of ensiled paulownia leaves in a high-forage diet on ruminal fermentation,methane production,fatty acid composition,and milk production performance of dairy cows 被引量:1
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作者 Haihao Huang Dorota Lechniak +7 位作者 Malgorzata Szumacher‑Strabel Amlan Kumar Patra Martyna Kozłowska Pawel Kolodziejski Min Gao Sylwester Ślusarczyk Daniel Petrič Adam Cieslak 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第1期339-357,共19页
Background:The use of industrial by-products rich in bioactive compounds as animal feeds can reduce greenhouse gas production.Paulownia leaves silage(PLS)was supplemented to dairy cows'diet and evaluated in vitro(... Background:The use of industrial by-products rich in bioactive compounds as animal feeds can reduce greenhouse gas production.Paulownia leaves silage(PLS)was supplemented to dairy cows'diet and evaluated in vitro(Exp.1;Rusitec)and in vivo(Exp.2,cannulated lactating dairy cows and Exp.3,non-cannulated lactating dairy cows).The study investigated the PLS effect on ruminal fermentation,microbial populations,methane production and concentration,dry matter intake(DMI),and fatty acid(FA)proportions in ruminal fluid and milk.Results:Several variables of the ruminal fluid were changed in response to the inclusion of PLS.In Exp.1,the p H increased linearly and quadratically,whereas ammonia and total volatile fatty acid(VFA)concentrations increased linearly and cubically.A linear,quadratic,and cubical decrease in methane concentration was observed with increasing dose of the PLS.Exp.2 revealed an increase in ruminal p H and ammonia concentrations,but no changes in total VFA concentration.Inclusion of PLS increased ruminal propionate(at 3 h and 6 h after feeding),isovalerate,and valerate concentrations.Addition of PLS also affected several populations of the analyzed microorganisms.The abundances of protozoa and bacteria were increased,whereas the abundance of archaea were decreased by PLS.Methane production decreased by 11%and 14%in PLS-fed cows compared to the control in Exp.2 and 3,respectively.Exp.3 revealed a reduction in the milk protein and lactose yield in the PLS-fed cows,but no effect on DMI and energy corrected milk yield.Also,the PLS diet affected the ruminal biohydrogenation process with an increased proportions of C18:3 cis-9 cis-12 cis-15,conjugated linoleic acid,C18:1 trans-11 FA,polyunsaturated fatty acids(PUFA),and reduced n6/n3 ratio and saturated fatty acids(SFA)proportion in milk.The relative transcript abundances of the 5 of 6 analyzed genes regulating FA metabolism increased.Conclusions:The dietary PLS replacing the alfalfa silage at 60 g/kg diet can reduce the methane emission and improve milk quality with greater proportions of PUFA,including conjugated linoleic acid,and C18:1 trans-11 along with reduction of SFA. 展开更多
关键词 Dairy cow Fatty acid composition in milk Methane emission Paulownia leaves
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Adsorption characteristics of humic acid-immobilized amine modified polyacrylamide/bentonite composite for cationic dyes in aqueous solutions 被引量:10
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作者 T. S. Anirudhan P. S. Suchithra 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第7期884-891,共8页
Humic acid-immobilized amine modified polyacrylamide/bentonite composite (HA-Am-PAA-B) was prepared and used as an adsorbent for the adsorption of cationic dyes (Malachite Green (MG), Methylene Blue (MB) and Cr... Humic acid-immobilized amine modified polyacrylamide/bentonite composite (HA-Am-PAA-B) was prepared and used as an adsorbent for the adsorption of cationic dyes (Malachite Green (MG), Methylene Blue (MB) and Crystal Violet (CV)) from aqueous solutions. The polyacrylamide/bentonite composite (PAA-B) was prepared by intercalative polymerization of acrylamide with Nabentonite in the presence of N,N'-methylenebisacrylamide as a crosslinking agent and hexamethylenediammine as propagater. PAA-B was subsequently treated with ethylenediammine to increase its loading capacity for HA. The surface characterizations of the adsorbent were investigated. The adsorbent behaved like a cation exchanger and more than 99.0% removal of dyes was detected at pH range 6.0-8.0. The capacity of HA-Am-PAA-B was found to decrease in the following order: MG〉MB〉CV. The kinetic and isotherm data were interpreted by pseudo-second order rate equation and Freundlich isotherm model, respectively. Experiments were carried out using binary solute systems to assess the competitive adsorption phenomenon. The experimental isotherm data for each binary solute combination of MG, MB and CV were analyzed using Sheindrof-Rebhun-Sheintuch (SRS) (multicomponent Freundlich type) equation. 展开更多
关键词 humic acid polymer/clay composite dye adsorption ISOTHERM regeneration
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Preparation and properties of short natural fiber reinforced poly(lactic acid) composites 被引量:5
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作者 于涛 李岩 任杰 《中国有色金属学会会刊:英文版》 CSCD 2009年第S3期651-655,共5页
The natural fiber/poly(lactic acid) (PLA) composites were prepared with ramie and jute short fiber as reinforcement and PLA as matrix. The mechanical and thermal properties of the composites were investigated. The res... The natural fiber/poly(lactic acid) (PLA) composites were prepared with ramie and jute short fiber as reinforcement and PLA as matrix. The mechanical and thermal properties of the composites were investigated. The results show that the properties of the composites are better than those of plain PLA. When the content of the fiber is 30%, the composites can get the best mechanical properties. The dynamic mechanical analysis results show that the storage moduli of the PLA/ramie and PLA/jute composites increase with respect to the plain PLA. The Vicat softening temperature of the composites is greatly higher than that of PLA. The results of thermogravimetric analysis show that adding fiber to the PLA matrix can improve the degradation temperature of PLA. 展开更多
关键词 poly(lactic acid) RAMIE JUTE composite
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STUDY ON CONCENTRATING SULFURIC ACID SOLUTION BY MEMBRANE DISTILLATION WITH METAL - PTFE COMPOSITE MEMBRANE 被引量:1
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作者 Guiqing Zhang Qixiu Zhang +1 位作者 Kanggen Zhou Aiping Luo 《Journal of Central South University》 SCIE EI CAS 1999年第2期95-98,共4页
concentrating sulfuric acid by membrane distillation in a flat sheet direct contact membrane distillation device with a self made metal PTFE composite membrane has been studied. The effect of sulfuric acid concentrati... concentrating sulfuric acid by membrane distillation in a flat sheet direct contact membrane distillation device with a self made metal PTFE composite membrane has been studied. The effect of sulfuric acid concentration of feed, the flowrate and liquor temperature in high temperature side and low temperature side on the flux and separation efficiency is investigated. The stability of this composite membrane is also inspected. The experimental results show that the metal PTFE composite membrane can be used in membrane distillation, and its properties are very stable. It is feasible to concentrate sulfuric acid by membrane distillation with this membrane. 展开更多
关键词 METAL PTFE composite MEMBRANE MEMBRANE DISTILLATION sulfuric acid
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Facile Synthesis of Gold Nanoparticle-loaded Carbon Nanofiber Composites and Their Electrocatalytic Activity Towards Dopamine, Ascorbic Acid and Uric Acid 被引量:1
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作者 TENG Hong LIU Yang YOU Tian-yan 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2011年第3期496-499,共4页
A facile approach for the synthesis of gold nanoparticle-loaded carbon nanofiber(Au/CNF) composites was developed. When applied to electrochemistry, these composites showed attractive performances such as high condu... A facile approach for the synthesis of gold nanoparticle-loaded carbon nanofiber(Au/CNF) composites was developed. When applied to electrochemistry, these composites showed attractive performances such as high conductivity and facile electron transfer kinetics. Under physiological conditions, the Au/CNF composite modified electrode exhibits highly electrocatalytic activity for the oxidation of dopamine, ascorbic acid and uric acid. Owing to the good selectivity for the simultaneous detection of these three species, the novel composites are promising for the development of effective electrochemical biosensors. 展开更多
关键词 Gold nanoparticle-loaded carbon nanofiber composite ELECTROSPINNING ELECTROCATALYSIS DOPAMINE Ascorbic acid Uric acid
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Ultrafine PdAg alloy nanoparticles anchored on NH2-functionalized 2D/2D TiO_(2) nanosheet/rGO composite as efficient and reusable catalyst for hydrogen release from additive-free formic acid at room temperature 被引量:2
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作者 Xi Zhao Ping Dai +3 位作者 Dongyan Xu Xumei Tao Xien Liu Qingjie Ge 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第8期455-464,I0010,共11页
A 2 D-2 D titanium dioxide nanosheet-reduced graphene oxide(TNS-r GO)composite with better electronic conductivity and hydrophilicity was prepared by the hydrothermal method.The as-obtained TNS-r GO composite was furt... A 2 D-2 D titanium dioxide nanosheet-reduced graphene oxide(TNS-r GO)composite with better electronic conductivity and hydrophilicity was prepared by the hydrothermal method.The as-obtained TNS-r GO composite was further functionalized with 3-aminopropyltriethoxysilane(APTES)to provide a large amount of-NH2 groups on the surface for anchoring ultrafine Pd Ag alloy nanoparticles with an average particle size of 1.69 nm by a facile wet reduction approach.Benefiting from the combined effects of well-dispersed Pd Ag alloy nanoparticles,facilitated electron transfer from TNS-r GO to Pd,and increased electron density of active sites,the Pd8 Ag_(1)/NH_(2)-TNS-r GO catalyst exhibited excellent activity towards dehydrogenation of formic acid without adding any additives at 298 K,corresponding to an initial turn over frequency as high as 1090 h-1,which is much higher than that of most other state-of-theart catalysts. 展开更多
关键词 Formic acid DEHYDROGENATION TNS-rGO composite PdAg alloy Amine-functionalization
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Preparation and Properties of Vegetable-Oil-Based Thioether Polyol and Ethyl Cellulose Supramolecular Composite Films
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作者 Ruyu Yan Jian Fang +7 位作者 Xiaohua Yang Na Yao Mei Li Yuan Nie Tianxiang Deng Haiyang Ding Lina Xu Shouhai Li 《Journal of Renewable Materials》 SCIE EI 2023年第4期1937-1950,共14页
Ethyl cellulose(EC),an important biomass-based material,has excellent film-forming properties.Nevertheless,the high interchain hydrogen bond interaction leads to a high glass transition temperature of EC,which makes i... Ethyl cellulose(EC),an important biomass-based material,has excellent film-forming properties.Nevertheless,the high interchain hydrogen bond interaction leads to a high glass transition temperature of EC,which makes it too brittle to be used widely.The hydroxyl group on EC can form a supramolecular system in the form of a non-covalent bond with an effective plasticizer.In this study,an important vegetable-oil-based derivative named dimer fatty acid was used to prepare a novel special plasticizer for EC.Dimer-fatty-acid-based thioether polyol(DATP)was synthesized and used to modify ethyl cellulose films.The supramolecular composite films of DATP and ethyl cellulose were designed using the newly-formed van der Waals force.The thermal stability,morphology,hydrophilicity,and mechanical properties of the composite films were all tested.Pure EC is fragile,and the addition of DATP makes the ethyl cellulose films more flexible.The elongation at the break of EC supramolecular films increased and the tensile strength decreased with the increasing DATP content.The elongation at the break of EC/DATP(60/40)and EC/DATP(50/50)was up to 40.3%and 43.4%,respectively.Noticeably,the thermal initial degradation temperature of the film with 10%DATP is higher than that of pure EC,which may be attributed to the formation of a better supramolecular system in this composite film.The application of bio-based material(EC)is environmentally friendly,and the novel DATP can be used as a special and effective plasticizer to prepare flexible EC films,making it more widely used in energy,chemical industry,materials,agriculture,medicine,and other fields. 展开更多
关键词 Ethyl cellulose dimeric fatty acid based thioether polyol supramolecular system composite films
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Novel Ni/CeO_2-Al_2O_3 composite catalysts synthesized by one-step citric acid complex and their performance in catalytic partial oxidation of methane 被引量:1
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作者 Changlin Yu Jiubiao Hu +1 位作者 Wanqin Zhou Qizhe Fan 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2014年第2期235-243,共9页
A series of novel Ni/CeOe-Al2O3 composite catalysts were synthesized by one-step citric acid complex method, The as-synthesized catalysts were characterized by N2 physical adsorption/desorption, X-ray diffraction (XR... A series of novel Ni/CeOe-Al2O3 composite catalysts were synthesized by one-step citric acid complex method, The as-synthesized catalysts were characterized by N2 physical adsorption/desorption, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, hydrogen temperature-programmed reduction (Hz-TPR), X-ray photoelectron spectroscopy (XPS) and thermogravimetry analysis (TGA). The effects of nickel content, calcination and reaction temperatures, gas hourly space velocity (GHSV) and inert gas dilution of N2 on their performance of catalytic partial oxidation of methane (CPOM) were investigated. Catalytic activity test results show that the highest methane conversion (〉85%), the best selectivities to carbon monoxide (〉87%) and to hydrogen (〉95%), the excellent stability and perfect Hz/CO ratio (2.0) can be obtained over Ni/CeO2-Al2O3 with 8 wt% Ni content calcined at 700 ℃ under the reaction condition of 750 ℃, CH4/O2 ratio of 2 : 1 and gas hourly space velocity of 12000 mL.h-1 .g-1. Characterization results show that the good catalytic performance of this composite catalyst can be contributed to its large specific surface area (~108 m2.g-1), small crystallite size, easy reducibility and low coking rate. 展开更多
关键词 citric acid complex ceria-alumina composite oxide nickel reduction catalytic partial oxidation or methane
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Mechanical and Thermal Properties of Apocynum and Ramie Fiber Mat Reinforced Polylactic Acid Composites 被引量:3
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作者 CAI Xinjuan MEI Xiaoxue +1 位作者 GHANI Muhammad Usman YAO Lan 《Journal of Donghua University(English Edition)》 CAS 2021年第2期99-105,共7页
With the increasing awareness of environmental protection and rational utilization of resources,natural fiber reinforced composites have shown broad development prospects.Apocynum fiber,known as the“king of wild fibe... With the increasing awareness of environmental protection and rational utilization of resources,natural fiber reinforced composites have shown broad development prospects.Apocynum fiber,known as the“king of wild fiber”,not only has moisture absorption,air permeability,and good mechanical properties but also has many health-related advantages such as antibacterial properties.In this study,four types of needle-punched Apocynum fiber and ramie fiber mat reinforced polylactic acid(PLA)composites were fabricated.Mechanical and thermal properties of the composites were tested and analyzed.The results showed that compared with those of the ramie fiber finish needle-punched mat reinforced composites,the tensile strength and the tensile modulus of Apocynum fiber finish needle-punched mat reinforced composites had increased by 15.3%and 60.1%,respectively.In comparison,the bending strength and the bending modulus were decreased by 21.8%and 7.6%,respectively.Moreover,compared with the Apocynum fiber finish needled-punched mat reinforced composites and the ramie fiber finish needle-punched mat reinforced composites,the Apocynum 50/ramie 50 finish needle-punched mat reinforced composites had the best tensile and bending properties.The after-fracture morphology was detected by a scanning electron microscope(SEM).The thermal properties of the composites were also characterized.It was found that the thermal properties of the four types of composites showed very similar behaviors. 展开更多
关键词 Apocynum fiber ramie fiber polylactic acid(PLA) composite mechanical property thermal property
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Superabsorbent Capability and High Retention Ability of China Clay(Kaolinite)/Polyacrylic Acid Composites for Aqueous Solution 被引量:1
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作者 Tanveer-Ul-Hassan Shah Mudassir Hussain Tahir +1 位作者 Ata ur Rahman He-wen Liu 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2019年第4期508-512,I0003,共6页
Majority of superabsorbent polymers (SAPs) yet reported either have low gel strength or high production cost. Therefore, we synthesized a novel polyacrylic acid-grafted China clay (Kaolinite) super-absorbent polymer c... Majority of superabsorbent polymers (SAPs) yet reported either have low gel strength or high production cost. Therefore, we synthesized a novel polyacrylic acid-grafted China clay (Kaolinite) super-absorbent polymer composite (SAPC) with high thermal stability, low cost of production and superior sorption and retention capability for water and salt solution. The resulting SAPCs were extensively characterized and analysed by X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Results suggested that the composites were thermally stable. Water absorbency increased with increase of clay content up to 45%, while further increase in clay content decreased the water absorbency. Percentage of acrylic acid (AA) and clay by weight shows the optimum absorbency in 35% and 40% respectively. Crosslinker and initiator contents were optimized to be 0.5% and 0.3% by weight respectively. The resulting polymer composite showed high water absorbency of about 785 g/g and 103 g/g of 1% NaCl solution with above 90% retention ability at 50 oC. 展开更多
关键词 China clay Superabsorbent composite KAOLINITE ABSORBENCY Acrylic acid
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Synthesis of ZSM-22/SAPO-11 composite molecular sieve-based catalysts with small crystallites and superior n-alkane hydroisomerization performance
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作者 Xue-Man Wang Cheng-Long Wen Yu Fan 《Petroleum Science》 SCIE EI CAS CSCD 2023年第4期2585-2595,共11页
To improve oil quality,ZSM-22/SAPO-11 composite molecular sieves were synthesized by adding ZSM-22 into a synthetic gel of SAPO-11 for n-decane hydroisomerization.The mass ratios of ZSM-22/(ZSM-22+SAPO-11)in the compo... To improve oil quality,ZSM-22/SAPO-11 composite molecular sieves were synthesized by adding ZSM-22 into a synthetic gel of SAPO-11 for n-decane hydroisomerization.The mass ratios of ZSM-22/(ZSM-22+SAPO-11)in the composite molecular sieves were optimized and the optimal ZSM-22/SAPO-11 composite(ZS-9)was obtained.The electrostatic repulsions between the ZSM-22 precursors and the SAPO-11 crystalline nuclei produced small ZSM-22 and SAPO-11 crystallites in ZS-9,which increased the specific surface area and mesopore volume and thereby exposed more acid sites.In comparison with conventional SAPO-11,ZSM-22 and their mechanical mixture,ZS-9 with smaller crystallites and the optimal medium and strong Brønsted acid centers(MSBAC)content displayed a higher yield of branched C_(10) isomers(81.6%),lower cracking selectivity(11.9%)and excellent stability.The correlation between the i-C_(10) selectivity and the MSBAC density of molecular sieves indicated that the selectivity for branched C_(10) isomers first increased and then decreased with increasing MSBAC density on the molecular sieves,and the maximum selectivity(87.7%)occurred with a density of 9.6×10^(−2)μmol m^(−2). 展开更多
关键词 ZSM-22/SAPO-11 composite molecular SIEVES Medium and strong brønsted acid centers Crystallite size Branched C_(10)isomers
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The Green Composites: Millet Husk Fiber (MHF) Filled Poly Lactic Acid (PLA) and Degradability Effects on Environment 被引量:1
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作者 Abba Alhaji Hammajam Abubakar Mohammed El-Jummah Zahari Nur Ismarrubie 《Open Journal of Composite Materials》 2019年第3期300-311,共12页
This study provides an overview on green composites degradability. Practically, the main drawbacks of using natural fibers are their poor dimensional stability, degradability and high degree of moisture absorption. Wh... This study provides an overview on green composites degradability. Practically, the main drawbacks of using natural fibers are their poor dimensional stability, degradability and high degree of moisture absorption. While, end use of product from natural fiber filled or reinforced composites has become subject of concern to material engineers and scientist. The major properties of natural fiber reinforced polymer composites are greatly dependent on the hydrophilic tendency and dimensional stability of the fibers used, morphology aspect ratio for long fiber, while voids for powder fibers. The effects of chemical treatments on cellulosic fibers that are used as reinforcements for thermoplastics were studied. The chemical source for the treatments is alkalization. The significance of chemically-treated natural fibers is seen through the improvement of mechanical properties. The untreated fiber composites degrade faster in municipal soil compared to treated fiber composites. 展开更多
关键词 DEGRADABILITY composite Fibers POLY LACTIC acid MILLET Husk
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The Studies on the Surface Organic Modification of Tourmaline Powder with Stearic Acid and Its Composite 被引量:1
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作者 Yingmo Hu 《Open Journal of Composite Materials》 2014年第3期148-156,共9页
Stearic acid modified tourmaline powder had been investigated to improve the compatibility and dispersed stability between tourmaline and polymer matrix. The experimental results indicated that the activation index wa... Stearic acid modified tourmaline powder had been investigated to improve the compatibility and dispersed stability between tourmaline and polymer matrix. The experimental results indicated that the activation index was 100% and contact angle reached 120° when the ratio of the ore slurry is 5:50, the dosage of stearic acid and p-toluenesulfonic acid is 10% and 0.5% (of tourmaline powder’s quantity) respectively with reaction at 80°C for 6.0 h, and the modified tourmaline exhibited an excellent hydrophobic property. The introduction of stearic groups reduced the reunion of tourmaline particles clearly and improved the dispersivity in polymers, and the amount of negative ions released of modified tourmaline increased obviously for both modified tourmaline powders and its composite with polyamide-66 compared to the unmodified tourmaline. Moreover, the structure of modified tourmaline was also characterized by means of Fourier Transform infrared spectroscopy, X-ray diffraction, thermal gravimetric analysis, scanning electron microscope. 展开更多
关键词 TOURMALINE Stearic acid SURFACE MODIFICATION NEGATIVE ION composites
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Poly(lactic acid)-starch/Expandable Graphite (PLA-starch/EG) Flame Retardant Composites 被引量:1
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作者 Mfiso Emmanuel Mngomezulu Adriaan Stephanus Luyt +1 位作者 Steve Anthony Chapple Maya Jacob John 《Journal of Renewable Materials》 SCIE 2018年第1期26-37,共12页
This work reports on the effect of commercial expandable graphite(EG)on the flammability and thermal decomposition properties of PLA-starch blend.The PLA-starch/EG composites were prepared by melt-mixing and their the... This work reports on the effect of commercial expandable graphite(EG)on the flammability and thermal decomposition properties of PLA-starch blend.The PLA-starch/EG composites were prepared by melt-mixing and their thermal stability,volatile pyrolysis products and flammability characteristics were investigated.The char residues of the composites,after combustion in a cone calorimeter,were analyzed with environmental scanning electron microscopy(ESEM).The thermal decomposition stability of the composites improved in the presence of EG.However,the char content was less than expected as per the combination of the wt%EG added into PLA-starch and the%residue of PLA-starch.The flammability performance of the PLA-starch/EG composites improved,especially at 15 wt%EG content,due to a thick and strong worm-like char structure.The peak heat release rate(PHRR)improved by 74%,the total smoke production(TSP)by 40%and the specific extinction area(SEA)by 55%.The improvements are attributed to the ability of EG to exfoliate at increased temperatures during which time three effects occurred:(i)cooling due to an endothermic exfoliation process,(ii)dilution due to release of H2O,SO2 and CO2 gases,and (iii)formation of a protective intumescent char layer.However,the CO and CO2 yields were found to be unfavorably high due to the presence of EG. 展开更多
关键词 Poly(lactic acid)-starch composites expandable graphite thermal stability flammability properties
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Preparation and Properties of Heat Resistant Polylactic Acid(PLA)/Nano-SiO2 Composite Filament 被引量:1
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作者 吴改红 刘淑强 +1 位作者 JIA Husheng DAI Jinming 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2016年第1期164-171,共8页
In order to improve the thermal properties of polylactic acid(PLA) filament,nano-SiO_2 was applied to mix with PLA,then they were spun as composite filament by melt-spinning.The dispersion of nano SiO_2 and the frac... In order to improve the thermal properties of polylactic acid(PLA) filament,nano-SiO_2 was applied to mix with PLA,then they were spun as composite filament by melt-spinning.The dispersion of nano SiO_2 and the fracture surfaces of filaments were studied by scanning electron microscopy(SEM).The properties of composite filament,such as orientation degree,mechanical properties,and surface friction properties,were analyzed.The thermal performances of composite filament were analyzed by differential scanning calorimetry(DSC) and thermo gravimetric analysis(TGA).The results showed that the nano-SiO_2 modified by 5% KH-550 could disperse evenly and loosely in nano-scale,and 1 wt% and 3 wt% nano-SiO_2 dispersed throughout PLA evenly.As the quantity of nano-SiO_2 increased,the properties of composite filament,such as orientation degree,friction coefficient,thermal decomposition temperature,and glass transition temperature,increased more or less.The breaking tenacity increased when 1 wt% SiO_2 was added in PLA,but declined when 3 wt% SiO_2 was added. 展开更多
关键词 polylactic acid PLA composite filament nano-silicon dioxide(nano-SiO_2) thermal property
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Microstructure and Characterization of Capric-stearic Acid/Modified Expanded Vermiculite Thermal Storage Composites 被引量:1
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作者 刘凤利 朱教群 +4 位作者 LIU Junhua MA Baoguo ZHOU Weibing LI Ruguang QIN Weigao 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第2期296-304,共9页
In order to improve the thermal storage capacity of expanded vermiculite(EV) based formstable composite PCM(FS-PCM) via organic modification of EV, first, EV was modified with a sodium stearate(Na St) as surface... In order to improve the thermal storage capacity of expanded vermiculite(EV) based formstable composite PCM(FS-PCM) via organic modification of EV, first, EV was modified with a sodium stearate(Na St) as surface modifier, and organic EV(OEV) with hydrophobicity and higher adsorption capacity for fatty acid was obtained. A novel capric-stearic acid eutectic(CA-SA)/OEV FS-PCM with high thermal storage capacity was then developed. OEV and CA-SA/OEV were characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), differential scanning calorimetry(DSC), thermal gravimetry(TG), and thermal cycling test. Results showed that OEV has obvious hydrophobicity and a higher adsorption capacity for fatty acid. Its adsorption ratio has increased by 48.71% compared with that of EV. CA-SA/OEV possesses high thermal storage density(112.52 J/g), suitable melting temperature(20.49 ℃), good chemical compatibility, excellent thermal stability and reliability, indicating great application potential for building energy efficiency. Moreover, organic modification of inorganic matrix may offer novel options for improving its adsorption capacity for organic PCMs and increasing heat storage capacity of corresponding FS-PCMs. 展开更多
关键词 organic expanded vermiculite capric-stearic acid eutectic form-stable composite PCMs thermal energy storage building envelope
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Biodiesel Production from Rhynchophorus ferrugineus Larvae Oil: Physichochemical Properties and Acid Composition of Oil as Affected by Oil Extraction Protocol
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作者 Arnaude Folepe Azemo Esther Julius K. Tangka Nsah-ko Tchoumboue 《Journal of Sustainable Bioenergy Systems》 2023年第4期117-130,共14页
Biodiesel, a renewable energy source made from natural oils and fats, can be produced using white raffia larvae as a raw material. These larvae have a high lipid content and a short life cycle, making them suitable fo... Biodiesel, a renewable energy source made from natural oils and fats, can be produced using white raffia larvae as a raw material. These larvae have a high lipid content and a short life cycle, making them suitable for this purpose. One crucial step in biodiesel production is oil extraction, and this study aimed to investigate how the extraction protocol affects the fuel properties of the oil. To study the impact of solvent type, solvent volume, and residence time on oil yield, 200 grams of Rhynchophorus ferrugineus were used in a Soxhlet extractor. The researchers examined the physicochemical properties and fatty acid composition of the crude grease using the European biodiesel standard (EN14214) and gas chromatography methods, respectively. The study found that hexane as a solvent produced the highest oil yield (64.44%) during a four-hour extraction period with a solvent ratio of 300 ml. Furthermore, the hexane-extracted oil had the highest iodine number (3.02 g/100 g) and cetane number (55.69). These values indicate favorable properties for biodiesel production. The Rhynchophorus ferrugineus larvae oil proved to be a rich source of monounsaturated fatty acids (76%), which were found to be significantly affected by the solvent type. Based on quality assessment, Rhynchophorus ferrugineus can be suitable for biodiesel production. In summary, under the given operational conditions, hexane is the most suitable solvent for Rhynchophorus ferrugineus oil extraction for biodiesel production. Further research in optimizing the extraction process can contribute to the efficient utilization of renewable energy sources like white raffia larvae for biodiesel production. 展开更多
关键词 BIODIESEL Extraction Process Fatty acid composition Physico-Chemical Properties Rhynchophorus ferrugineus Larvae
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