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Effect of Tannin and Nanocellulose on Properties of Sustainable Cellulose Acetate Films
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作者 JoséMarcelo Faria de Queiroz Júnior Nathália Ramosde Melo +2 位作者 Ulisses Oliveira Costa Letícia Vitorazi Flavia Lega Braghiroli 《Journal of Renewable Materials》 2026年第2期144-170,共27页
The development of sustainable materials has encouraged the use of biopolymers as alternatives to synthetic polymers.Polymeric films have stood out for their high potential in environmentally sustainable applications.... The development of sustainable materials has encouraged the use of biopolymers as alternatives to synthetic polymers.Polymeric films have stood out for their high potential in environmentally sustainable applications.Conventional cellulose acetate(CA)-based films are attractive due to their biodegradability and film-forming ability.However,their functional performance often requires enhancement through the incorporation of additives.In this context,two bio-based additives were investigated:condensed tannin(0%,5%and 10%wt.),a natural polyphenol known for its antioxidant and antimicrobial properties,and nanocrystalline cellulose(CNC)(0%,0.5%and 1%wt.),which act as reinforcing agents to improve mechanical strength and barrier properties.The results showed that tannin generally enhanced mechanical strength and surface uniformity while imparting contact-based antimicrobial activity.CNC reduced water uptake and improved thermal stability,but when used alone,it tended to lower mechanical performance and increase surface roughness.The combination of CNC and tannin produced performance shifts that depended strongly on their relative concentrations,with no consistent synergistic effect across all properties.In certain balanced ratios,CNC benefited fromtannin’smatrix-stabilizing effect,leading to improved strength or reduced moisture absorption.Antimicrobial activity in acetic acid–based films was linked to residual acidity,whereas in acetonebased films,tannin alone was responsible for the antimicrobial effect by contact.These findings highlight that the physicochemical,mechanical,and functional performance of CA films(CAFs)is governed not only by additive type but also by the precise interplay between CNC and tannin,underscoring the need for formulation strategies tailored to the requirements of specific applications. 展开更多
关键词 Cellulose derivatives crystalline nanocellulose condensed tannin biobased films CHARACTERIZATION
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Biomass aerogel based on chitosan and bayberry tannin for uranium recovery from aqueous solution
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作者 Gui-Qiang He Jin-Fan Ou +3 位作者 Yan-Xia Wei Ai-Xia Lu Dan Lin Jian Zhou 《Nuclear Science and Techniques》 2026年第3期79-89,共11页
Many adsorbents have been developed for uranium recovery to ensure global energy and environmental security.However,most reported adsorbents involve complex preparation process and rely heavily on petrochemical feedst... Many adsorbents have been developed for uranium recovery to ensure global energy and environmental security.However,most reported adsorbents involve complex preparation process and rely heavily on petrochemical feedstocks,which undoubtedly increases carbon emissions from production in the nuclear industry.Here,a biomass aerogel(CS-BT)is prepared by the facile cross-linking of chitosan and bayberry tannins with glutaraldehyde.U(Ⅵ)can be adsorbed by hydroxyl groups on CS-BT aerogel via chelation,and the maximum adsorption capacity of the obtained aerogel to U(Ⅵ)is 140 mg·g^(-1)and the removal rate reaches up to 99%(at 298.15 K,pH=5.0).The pseudo-second-order kinetics model and Freundlich model can better match the adsorption process of CS-BT aerogel,implying that its adsorption is a chemical adsorption process dominated by multilayer adsorption.The thermodynamic results show that the adsorption process of U(Ⅵ)by CS-BT aerogel is spontaneous and exothermic.Hence,our biomass aerogel can effectively extract uranium from water,contributing to the sustainable development of the nuclear industry. 展开更多
关键词 Biomass aerogel CHITOSAN Bayberry tannin Uranium recovery
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New Rigid Furan Biofoams Based on Hydrolysable Chesnut(Castanea sativa)Tannin by Chemical Expansion
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作者 João Vitor Dorini Falavinha Pedro Henrique Gonzales De Cademartori +2 位作者 Philippe Gérardin Antonio Pizzi Christine Gérardin-Charbonnier 《Journal of Renewable Materials》 2025年第4期687-697,共11页
Tannins are polyphenols widely present in the plant kingdom,commonly divided into two groups:condensed and hydrolysable tannins.Sustainable furanic bio-foams based on condensed tannins have been largely studied,but li... Tannins are polyphenols widely present in the plant kingdom,commonly divided into two groups:condensed and hydrolysable tannins.Sustainable furanic bio-foams based on condensed tannins have been largely studied,but little is described about the use of hydrolysable tannins for this material.This study examined the potential of hydrolysable chestnut tannin in comparison to condensed mimosa tannins to produce furanic foams by chemical expansion.Due to the low reactivity of the hydrolysable tannin,the use of an external source for its polymerization and curing was necessary.Through Fourier transform infrared spectroscopy(FTIR)chromatography,it was possible to observe that the new foams presented small differences in functional groups compared to the condensed tannin foams,presenting peaks related to carboxyl groups.In terms of physical properties,the chestnut foams showed an apparent density 36%higher than the conventional mimosa tannin foams and a superior hydrophilic character.In terms of thermal properties,both foams exhibit high thermal stability,with the acacia tannin foam being slightly superior.In summary,this research paves the way for new applications of hydrolysable tannins in bio-foams and materials science. 展开更多
关键词 tannin foams furfuryl alcohol hydrolysable tannin CHESTNUT
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Photothermal MXene-embedded tannin-Eu^(3+)particles as in situ bacterial vaccines for accelerating healing of wounds infected by seawater immersion and providing persistent anti-infection effects
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作者 Zhentao Li Ting Song +3 位作者 Yanpeng Jiao Zijing Zhu Yang Liao Zonghua Liu 《Bio-Design and Manufacturing》 2025年第1期116-133,I0045-I0050,共24页
The low temperature,high salt content,and bacterial composition of a seawater environment can induce severe infections in open wounds,thus impeding wound healing.To date,numerous wound dressings have been developed fo... The low temperature,high salt content,and bacterial composition of a seawater environment can induce severe infections in open wounds,thus impeding wound healing.To date,numerous wound dressings have been developed for injuries and various antibacterial functions.However,ordinary antibacterial strategies could not provide long-term resistance to infections and could not promote wound healing.Here,we proposed a strategy for enhancing resistance to seawater immersion wound infection by killing bacteria and delivering bacterial antigens in situ.Specifically,MXene-embedded tannin-Eu^(3+)(M@TA-Eu)particles were constructed to effectively alleviate injuries infected through seawater immersion and persistently fight infection by forming in situ bacterial vaccines and immune memory.In the particle,the platform composed of TA and Eu3+exhibited provascularization and antigen presentation effects.MXenes with near-infrared photothermal effect were introduced to kill the bacteria,promote the recruitment of antigen presentation cells,and ultimately enhance vaccination efficacy.Experimental results showed that the particles not only effectively accelerated the healing of injuries by relieving wound inflammation and inhibiting bacteria but also produced a potent vaccination by forming in situ bacterial vaccines.Therefore,the M@TA-Eu particles are novel materials for high-grade anti-infection dressing. 展开更多
关键词 MXene tannin Wound healing ANTI-INFECTION In situ vaccine
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Physical and Mechanical Properties of Gmelina Wood(Gmelina arborea Roxb.)Modified with Furfuryl Alcohol-Tannin
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作者 Mahdi Mubarok Pirda Maharani Nafisah +11 位作者 Adi Santoso Saefudin Efrida Basri Yusuf Sudo Hadi Adik Bahanawan Rohmah Pari Imam Busyra Abdillah Jingjing Liao Dede Hermawan Trisna Priadi Philippe Gérardin Wayan Darmawan 《Journal of Renewable Materials》 2025年第4期731-752,共22页
Furfurylation,a renowned chemical modification technique,uses furfuryl alcohol to enhance the properties of wood.This technology can be further refined by incorporating renewable tannins,which promote cross-linking wi... Furfurylation,a renowned chemical modification technique,uses furfuryl alcohol to enhance the properties of wood.This technology can be further refined by incorporating renewable tannins,which promote cross-linking with furfuryl alcohol.This study investigates the effects of furfurylation and tannin-modified furfurylation on the physical and mechanical properties of tropical Gmelina wood(Gmelina arborea Roxb.).Experiments involved impregnating Gmelina wood with aqueous solutions of furfuryl alcohol(FA)at 40%and 70%concentrations,as well as FA-tannin combinations(FA 40%-TA and FA 70%-TA),followed by polymerization at 103℃.The results demonstrated that both FA and FA-tannin treatments significantly improved the wood’s physical and mechanical properties.Notably,FA-tannin treatments achieved anti-swelling efficiency comparable to FA alone.However,the addition of tannins(FA 70%-TA)enhanced leaching resistance by up to 47%,contributing to a more environmentally sustainable modification process.Mechanically,the inclusion of tannins in FA 70%-TA slightly increased the modulus of elasticity(14%~8732 kg/cm^(2))and the modulus of rupture(9%~40.9 kg/cm^(2)).Furthermore,the tannin addition imparted a darker color to the modified wood,enhancing its aesthetic appeal.This study highlights the potential of tannin-modified furfurylation to advance wood modification technology,combining improved performance with environmental benefits. 展开更多
关键词 Chemical modification furfurylation gmelina wood physical-mechanical properties tannin
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Integrated transcriptomics and metabolomics reveal multi‑target mechanisms of tannins against Clostridium perfringens and necrotic enteritis
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作者 Huiping Xu Lu Gong Yuming Guo 《Journal of Animal Science and Biotechnology》 2025年第5期2134-2151,共18页
Background Clostridium perfringens is a pathogen that secretes multiple toxins,impacting humans and animals.It can cause intestinal diseases such as necrotic enteritis.Although tannins inhibit C.perfringens proliferat... Background Clostridium perfringens is a pathogen that secretes multiple toxins,impacting humans and animals.It can cause intestinal diseases such as necrotic enteritis.Although tannins inhibit C.perfringens proliferation,the precise underlying mechanisms are unclear.Objective This study integrated transcriptomics and metabolomics to systematically investigate the mechanism by which tannins,specifically pentagalloylglucose(PGG)and tannic acid(TA),inhibit C.perfringens and potential pathways to alleviate infection in vivo.Results Ion concentration measurements,flow cytometric analysis,and transmission electron microscopy revealed that PGG and TA damaged the cell membrane structure of C.perfringens,triggering cytoplasmic content leakage.Additionally,PGG and TA significantly affected C.perfringens at the transcriptional and metabolic levels.Bioinformatics analysis revealed that PGG and TA induced amino acid restriction,disrupted energy metabolism,and impeded the ability of C.perfringens to sense and respond to the external environment.In an in vitro C.perfringens-infected intestinal cell model,PGG and TA boundαtoxin,significantly reduced the mRNA expression of inflammatory factors,and improved intestinal barrier function and cell viability.Compared to PGG,TA exhibited stronger inhibitory activity against C.perfringens and binding toαtoxin.In vivo,PGG and TA alleviated C.perfringens-induced weight loss in mice,improved intestinal villi morphology,and reduced intestinal inflammation and tight junction gene dysregulation.Conclusion These findings indicate that tannins inhibit C.perfringens,improve gut tissue integrity and reduce inflammation,demonstrating their multi-target effects of resisting intestinal diseases caused by harmful bacteria.This offers new insights for plant polyphenol-based strategies against necrotic enteritis. 展开更多
关键词 Clostridium perfringens Intestinal epithelial cells METABOLOME Necrotic enteritis tanninS TRANSCRIPTOME
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Dietary hydrolysable tannin improves intestinal health of largemouth bass(Micropterus salmoides):insights from NF-κB signaling pathway and arachidonic acid metabolism
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作者 Manqi Yang Dahai Jiang +9 位作者 Zhangyi Xiao Weibin Lai Kai Chen Shuwen Xu Yuanyi Zuo Liangliang Zhang Liming Lu Xiaoping Rao Chunxiao Zhang Jianchun Jiang 《Journal of Animal Science and Biotechnology》 2025年第6期2966-2985,共20页
Background To more effectively address the scarcity resources and elevated costs associated with fishmeal(FM),the utilization of cottonseed protein concentrate(CPC)as an alternative in aquaculture feeds has become inc... Background To more effectively address the scarcity resources and elevated costs associated with fishmeal(FM),the utilization of cottonseed protein concentrate(CPC)as an alternative in aquaculture feeds has become increasingly prevalent.However,high levels of CPC substitution for FM have been reported to suppress the growth of fish and impair intestinal health.Hydrolysable tannin(HT)has been reported to exhibit biological activities such as antiinflammatory and antioxidant activities,but whether the HT can generate positive biological effects on the intestinal health of largemouth bass(Micropterus salmoides)remains unknown.Largemouth bass(initial weight:6.03±0.01 g)were subjected to an 8-week feeding trial with three different diets:a basic diet(named as the NC),a high CPC diet(in which CPC replaced 75%of the FM protein in the NC diet,named as the HC),and an additive diet(1.25 g/kg of the HT was added to the HC diet,named as the HCH)to explore the potential benefits of HT on intestinal health.Results The HC treatment significantly reduced the weight gain rate of fish,increased the feed conversion ratio,and induced intestinal inflammation.However,the HCH treatment could alleviate the adverse impacts of the HC diet,as evidenced by the promotion of growth and feed utilization,increased activity of digestive enzymes and antioxidant capacities,downregulated expression of pro-inflammatory factors,and maintenance of the integrity of intestinal barrier.Metabolomic analysis revealed that HCH treatment could reduce the pro-inflammatory active substances produced by arachidonic acid metabolism,including prostaglandin F2α(PGF2α)and leukotriene B4(LTB4).Transcriptomic results indicated that dietary HT might alleviate intestinal inflammation by suppressing the activation of the NF-κB signaling pathway.Furthermore,correlation analysis demonstrated that the metabolites PGF2αand LTB4,derived from arachidonic acid,exhibited a significant positive correlation with the expression of genes associated with proinflammatory responses within the NF-κB signaling pathway.Conclusions The study indicates that the HT mitigates the growth retardation and intestinal inflammation resulting from the HC diet on largemouth bass. 展开更多
关键词 Arachidonic acid metabolism Hydrolysable tannin Intestinal inflammation Largemouth bass NF-κB signaling pathway Plant-based protein source
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Tannin-Based Biofoams-A Review 被引量:10
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作者 Antonio Pizzi 《Journal of Renewable Materials》 SCIE 2019年第5期477-492,共16页
This review details the development of tannin-based biofoams for fire resistance and acoustic insulation and details the different varieties of these foams that have been developed,from tannin-furanic self-blowing foa... This review details the development of tannin-based biofoams for fire resistance and acoustic insulation and details the different varieties of these foams that have been developed,from tannin-furanic self-blowing foams to tannin-furanic polyurethanes and finally non-isocyanate tannin-basedcarbohydrates polyurethanes(NIPU). 展开更多
关键词 Biofoams tanninS tannin-furanic tannin-carbohydrates nonisocyanate polyurethanes(NIPU)
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Covalent and Ionic Bonding between Tannin and Collagen in Leather Making and Shrinking:A MALDI-ToF Study 被引量:3
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作者 Antonio Pizzi 《Journal of Renewable Materials》 SCIE EI 2021年第8期1345-1364,共20页
Collagen powder hydrolysates were reacted with a solution of commercial mimosa bark tannin extract.The mixture was prepared at ambient temperature and prepared at 80°C to determine what reactions,if any,did occur... Collagen powder hydrolysates were reacted with a solution of commercial mimosa bark tannin extract.The mixture was prepared at ambient temperature and prepared at 80°C to determine what reactions,if any,did occur between the collagen protein through its amino acids and the polyphenolic condensed tannin.The reaction products obtained were analyzed by matrix assisted laser desorption ionization time-of-flight(MALDI ToF)mass spectrometry.Reactions between the two materials did appear to occur,with the formation of a relatively small proportion of covalent and ionic linkages at ambient temperature but a considerable proportion of covalent linkages tannin-protein amino acids and the disappearance of ionic bonds.The linkages between the two materials appeared to be by amination of the phenolic–OHs of the tannin by the amino groups of the non-skeletal side chains of arginine,and by esterification by the–COOH groups of glutamic and aspartic acid of the aliphatic alcohol-OH on the C3 site of the flavonoid units heterocycle of the tannin.The proportion of covalent linkages increases markedly and predominate with increasing temperatures.This tightening of the tannin-protein covalent network formed may be an additional contributing factor both to leather wear resistance and performance as well to leather shrinking when this is subjected to excessive temperatures. 展开更多
关键词 LEATHER collagen vegetal tannins tanninG tannin-protein reactions covalent bonds leather cross-linking leather shrinkage MALDI
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Chemistry and ecological significance of tannins
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作者 赵晓虹 陈化鹏 周宣滨 《Journal of Forestry Research》 SCIE CAS CSCD 1998年第4期280-282,共3页
This paper summarized of the chemistry characteristics of tannins and their various adverse effects onmammalian herbivore, including the chemical nature of hydrolyzable and condensed tannins, their analysis mathods, a... This paper summarized of the chemistry characteristics of tannins and their various adverse effects onmammalian herbivore, including the chemical nature of hydrolyzable and condensed tannins, their analysis mathods, and the tannins antifeedant mechanisms. 展开更多
关键词 tanninS Condensed tannins Hydrolyzable tannins ANTIFEEDANTS DEFENCE
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Self-Cross-Linked Tannin-Aminated Tannin Surface Coatings for Particleboard
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作者 Bengang Zhang Antonio Pizzi +2 位作者 Mathieu Petrissans Anelie Petrissans Colin Baptiste 《Journal of Renewable Materials》 EI 2023年第12期4097-4121,共25页
Aminated tannins were prepared by reacting mimosa condensed tannin extract with ammonia yielding the substitution of many,if not all of the tannin hydroxyl groups with–NH_(2)groups.A tannin-aminated tannin(ATT)partic... Aminated tannins were prepared by reacting mimosa condensed tannin extract with ammonia yielding the substitution of many,if not all of the tannin hydroxyl groups with–NH_(2)groups.A tannin-aminated tannin(ATT)particleboard coating was then prepared by reacting raw tannin extract with aminated tannin extract and thus cross-linking the two by substituting tannin’s hydroxyl groups with the–NH_(2)groups on the aminated tannin to form–NH-bridges between the two.The resulting particleboard coating gave encouraging results when pressed at 180℃for 3 min.Conversely,the system in which tannin was reacted/cross-liked with urea(ATU)by a similar amination reaction did not perform as well as the ATT system,and this even when a higher curing temperature and longer hot press time were used.In particular its water repellence was worse probably due to the presence of urea and such a system with lower reactivity.Nonetheless,substituting the tannin–OHs with the urea–NH_(2)groups appeared to also take place.ATT gave better results than ATU as regards water repellence and mechanical resistance as shown by the cross cut test.The ATT system was shown to be between 95%and 98%biosourced.The difference appeared to be due,by TMA analysis,to the much faster formation of the ATT hardened network leading to a better cross-linked polymer coating.The chemical species formed for both the ATT and ATU system were studied by MALDI ToF and CP MAS^(13)C NMR. 展开更多
关键词 Biocoatings PARTICLEBOARD aminated tannin cross-linked tannin-aminated tannin tannin-urea cross links water repellence cross cut test MALDI ToF ^(13)C NMR
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Lead Removal from Aqueous Solutions Using Novel Gel Adsorbent Synthesized from Natural Condensed Tannin 被引量:3
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作者 占新民 赵璇 +1 位作者 AKANE Miyazaki YOSHIO Nakano 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第4期426-430,共5页
Lead has caused serious environmental pollution due to its toxicity, accumulation in food chains and persistence in nature. In this paper, removal of lead from aqueous solutions is investigated using a novel gel adsor... Lead has caused serious environmental pollution due to its toxicity, accumulation in food chains and persistence in nature. In this paper, removal of lead from aqueous solutions is investigated using a novel gel adsorbent synthesized from natural condensed tannin. The novel adsorbent performs in aqueous solutions as a weak base with valid basic groups of 1.2mmol·g-1 tannin gel particles and therefore results in the elevation of pH value of aqueous solutions. Even when initial pH is 3.6, final pH at equilibrium can climb up to 6.5 that is above the pH value for Pb(OH)2 precipitation formation and then lead can be removed from wastewater by this so-called surface precipitation. The adsorption isotherm can be expressed by the Langmuir equation and the maximum capacity for adsorption of Pb is up to 92 mg·g-1 (based on dry adsorbent) when initial pH value is 3.6. Hence, the adsorbent does offer favorable properties in lead removal with respect to its high adsorption capacity at low initial pH value, which is advantageous to lead removal from acidic wastewater. A model is put forward to describe the individual adsorption phenomenon of the tannin gel adsorbent. 展开更多
关键词 condensed tannin lead removal surface precipitation tannin gel adsorbent
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Hydrolysable Chestnut Tannin Extract Chemical Complexity in Its Reactions for Non-Isocyanate Polyurethanes(NIPU)Foams 被引量:3
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作者 Elham Azadeh Antonio Pizzi +1 位作者 Christine Gerardin-Charbonnier Philippe Gerardin 《Journal of Renewable Materials》 SCIE EI 2023年第6期2823-2848,共26页
Non-isocyanate polyurethane(NIPU)foams from a commercial hydrolysable tannin extract,chestnut wood tannin extract,have been prepared to determine what chemical species and products are taking part in the reactions inv... Non-isocyanate polyurethane(NIPU)foams from a commercial hydrolysable tannin extract,chestnut wood tannin extract,have been prepared to determine what chemical species and products are taking part in the reactions involved.This method is based on two main steps:the reaction with dimethyl carbonate and the formation of urethane bonds by further reaction of the carbonated tannin with a diamine-like hexamethylene diamine.The hydroxyl groups on the tannin polyphenols and on the carbohydrates intimately linked with it and part of a hydrolysable tannin are the groups involved in these reactions.The carbohydrate skeleton of the hydrolysable tannin is also able to participate through its hydroxyl groups to the same two reactions rendering the whole molecular complex able to react to form NIPUs.The analysis by Matrix-Assisted Laser Desorption Ionization(MALDI-TOF)mass spectrometry and 13C Nuclear Magnetic Resonance(13C NMR)to further investigate the reaction mechanisms involved revealed the unsuspected complexity of chestnut hydrolysable tannin,with different fragments reacting in different manners forming a hardened network of considerable complexity.As the morphology and performance of these types of foams changes slightly with the change in the amount of glutaraldehyde and hexamine hardeners,the best performing foam formulation previously determined was scanned by SEM and analysed chemically for the structures formed. 展开更多
关键词 Hydrolysable tannin chestnut tannin non-isocyanate bio polyurethanes NIPU MALDI-TOF ^(13)C NMR SEM bio-based materials
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Self-Blowing Non-Isocyanate Polyurethane Foams Based on Hydrolysable Tannins 被引量:2
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作者 Elham Azadeh Xinyi Chen +3 位作者 Antonio Pizzi Christine Gérardin Philip Gérardin Hisham Essawy 《Journal of Renewable Materials》 SCIE EI 2022年第12期3217-3227,共11页
ABSTRACT Non-isocyanate polyurethane(NIPU)foams using a hydrolysable tannin,also vulgarly called tannic acid,namely here commercial chestnut wood tannin extract was prepared.Compression strength did not appear to depe... ABSTRACT Non-isocyanate polyurethane(NIPU)foams using a hydrolysable tannin,also vulgarly called tannic acid,namely here commercial chestnut wood tannin extract was prepared.Compression strength did not appear to depend on the foam apparent density while the formulation composition of the NIPU foams has been shown to be more determinant.These NIPU foams appeared to be self-extinguishing once the high temperature flame is removed.The ignition time gave encouraging results but for improved fire resistance the foams may need some fire-retardant addition.FTIR spectrometry showed the formation of non-isocyanate urethane linkages.Thermogravimetric analysis indicated a good thermal resistance of these foams,with thermal degradation following four phases.First in the interval 25℃–120℃ range,mainly evaporation of water occurs with a maximal loss of 10%weight.In the 150℃–450℃ temperature range foams mass loss is of almost 70%.In particular in the 125℃–275℃ range occurs the degradation of some small molecular weight substances.In the 500℃–790℃ temperature range the foams do not present any further large degradation. 展开更多
关键词 Non-isocyanate biopolyurethanes(NIPU) biofoams chestnut tannin hydrolysable tannins self-extinguishing
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Kinetics of non-catalyzed hydrolysis of tannin in high temperature liquid water 被引量:2
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作者 Li-li LU Xiu-yang LU Nan MA 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2008年第5期401-406,共6页
High temperature liquid water(HTLW) has drawn increasing attention as an environmentally benign medium for organic chemical reactions,especially acid-/base-catalyzed reactions. Non-catalyzed hydrolyses of gallotannin ... High temperature liquid water(HTLW) has drawn increasing attention as an environmentally benign medium for organic chemical reactions,especially acid-/base-catalyzed reactions. Non-catalyzed hydrolyses of gallotannin and tara tannin in HTLW for the simultaneous preparation of gallic acid(GA) and pyrogallol(PY) are under investigation in our laboratory. In this study,the hydrolysis kinetics of gallotannin and tara tannin were determined. The reaction is indicated to be a typical consecutive first-order one in which GA has formed as a main intermediate and PY as the final product. Selective decomposition of tannin in HTLW was proved to be possible by adjusting reaction temperature and time. The present results provide an important basic data and reference for the green preparation of GA and PY. 展开更多
关键词 High temperature liquid water GALLOtannin Tara tannin Non-catalyzed hydrolysis KINETICS
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Tannin–Phenol Formaldehyde Resins As Binders for Cellulosic Fibers: Mechanical Properties 被引量:1
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作者 A.S. Hussein K.I. Ibrahim K. M. Abdulla 《Natural Resources》 2011年第2期98-101,共4页
In this study Eucalyptus tannin (T) was isolated from outer bark of Eucalyptus trees;as sodium phenoxide salt and used as extender or copolymer into phenol formaldehyde (PF) resin at five percent (10, 20, 30, 40 and 5... In this study Eucalyptus tannin (T) was isolated from outer bark of Eucalyptus trees;as sodium phenoxide salt and used as extender or copolymer into phenol formaldehyde (PF) resin at five percent (10, 20, 30, 40 and 50)% W/W. Tan-nin-phenol formaldehyde (TPF) and tannin formaldehyde-phenol formaldehyde (TFPF) resins that synthesized in this study were evaluated as adhesive material for cellulosic fibers by study the mechanical properties of the composite sheets .The results show that the substituting of (PF) with tannin at (10 –50)% W/W give resins with mechanical properties comparable or near to those of pure (PF) , where the tensile strength at break (Tb) ranging from 15.15 Mpa to 22.27 Mpa as compared with 17.6 Mpa for pure (PF);while the impact strength properties (Im) of composites sheets increased with increased the (T) percents which were about 5.16 KJ/m2 for (TPF – 10%) and 7.21 KJ/m2 for (TPF - 50%) .On the other hand modification of (T) to tannin formaldehyde resin (TF) appear less performance at the results of this study , this effect probably to low penetration of (TFPF) resins between the small voids of cellulose fibers when soaked it in resin solutions. In general the results of this study indicate that the Eucalyptus tannin can be used for par-tial substitution of (PF) to produce resins with feasible mechanical properties and can be used in some applications of (PF) resins. 展开更多
关键词 tannin tannin-formaldehyde RESINS Phenol- FORMALDEHYDE RESINS Mechanical PROPERTIES
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Removal of lead from aqueous solutions by condensed tannin gel adsorbent
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作者 ZHANXin-min ZHAOXuan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2003年第1期102-106,共5页
Lead has caused serious environmental pollution due to its toxicity, accumulation in food chains and persistence in nature. In this paper, lead removal from aqueous solutions was investigated using condensed tannin ge... Lead has caused serious environmental pollution due to its toxicity, accumulation in food chains and persistence in nature. In this paper, lead removal from aqueous solutions was investigated using condensed tannin gel adsorbent synthesized from a natural tannin compound. It is found that the adsorption is strongly affected by pH values of aqueous solutions. Within pH range of 3 5—6, when initial lead concentration is 100 mg/L, removal efficiency is more than 90%. Adsorption equilibrium is reached within 150 minutes. The adsorption isotherm fits well with the Langmuir equation, by which the saturated adsorption uptake of 190 mg Pb 2+ /g dry tannin gel adsorbent is obtained. By means of thermodynamics analysis, it is revealed that the process is exothermic and the adsorption heat is up to 38 4 kJ/mol. With respect to high efficiency, moderate pH requirement and minimized second pollution, the tannin gel adsorbent exhibits a promising potential in the removal of lead from wastewater. 展开更多
关键词 lead removal Mimosa tannin synthesis tannin gel adsorbent
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A Review of Soy-Tannin Gelling for Resins Applications
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作者 Antonio Pizzi 《Journal of Renewable Materials》 SCIE EI 2023年第1期1-25,共25页
Soy flour(SF),soy protein and soy protein isolates(SPI)have been the focus of increasing research on their application as new materials for a variety of applications,mainly for wood adhesives and other resins.Tannins ... Soy flour(SF),soy protein and soy protein isolates(SPI)have been the focus of increasing research on their application as new materials for a variety of applications,mainly for wood adhesives and other resins.Tannins too have been the focus of increasing research for similar applications.While both materials are classed as non-toxic and have achieved interesting results the majority of the numerous and rather inventive approaches have still relied on some sort of hardeners or cross-linkers to bring either of them or even their combination to achieve acceptable results.The paper after a presentation of the two materials and their characteristics concentrates on the formation of gels,gelling and even hardening in the case of soy-tannin combined resins.The chapter than finishes with details of the formation of resins giving suitable wood adhesive of acceptable performance by the covalent coreaction of soy protein and tannin without any other hardener,thus totally bio-sourced,non-toxic and environment friendly as a base of further advances to expect in future by these two materials combination. 展开更多
关键词 SOY tannin soy-tannin coreaction GELLING HARDENING WOOD
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Flexible Biofoams Based on Furanics and Fatty Acids Esterified Tannin
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作者 Elham Azadeh Ummi Hani Abdullah +3 位作者 Christine Gerardin Antonio Pizzi Philippe Gerardin Cesar Segovia 《Journal of Renewable Materials》 EI 2023年第10期3625-3645,共21页
Water repellant,flexible biofoams using tannin esterified with various fatty acid chains,namely lauric,palmitic and oleic acids,by reaction with lauryl chloride,palmitoyl chloride,and oleyl chloride were developed and... Water repellant,flexible biofoams using tannin esterified with various fatty acid chains,namely lauric,palmitic and oleic acids,by reaction with lauryl chloride,palmitoyl chloride,and oleyl chloride were developed and their characteristics compared with the equivalently esterified rigid biofoams.Glycerol,while initially added to control the reaction temperature,was used as a plasticizer yielding flexible biofoams presenting the same water repellant character that the equivalent rigid foams.Acetaldehyde was used as the cross-linking agent instead of formaldehyde,as it showed a better performance with the esterified tannin.The compression results showed a significant decrease of the Modulus of Elasticity(MOE)of the flexible foams in relation to that of the rigid foams,confirming their flexible character.The lauryl-and palmitoyl-esterified biofoams presented similar mechanical properties,while the oleyl-esterified biofoam presented different mechanical and morphological result not really showing the expected flexibility.Both the esterified rigid and flexible tannin-based biofoams showed good water resistance and their sessile drop contact angle analysis as a function of time confirmed this characteristic.Scanning Electron Microscope(SEM)analysis showed the flexible foams to present a higher proportion of closed cells than the rigid foams.Conversely,the cells depth of the flexible foams was lower than that of the rigid foam.As regards their thermal resistance,the flexible foams showed a slight loss of mass compared to the rigid ones without glycerol.Both types of foams presented much lower surface friability of non-esterified rigid foams. 展开更多
关键词 Flexible tannin-furanic foams esterified tannins water repellence TGA SEM compression
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Biochemical changes in phenols,flavonoids,tannins,vitamin E,β-carotene and antioxidant activity during soaking of three white sorghum varieties 被引量:7
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作者 Abd El-Moneim MR Afify Hossam S El-Beltagi +1 位作者 Samiha M Abd El-Salam Azza A Omran 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2012年第3期203-209,共7页
Objective:To investigate the changes in total phenols,flavonoids,tannins,vitamin E, β-carotene and antioxidant activity during soaking of three white sorghum varieties.Methods: The changes in total phenols,total ilav... Objective:To investigate the changes in total phenols,flavonoids,tannins,vitamin E, β-carotene and antioxidant activity during soaking of three white sorghum varieties.Methods: The changes in total phenols,total ilavonoids,tannins,phenolic acids compounds,flavonoid components,vitamin E,P-carotene and antioxidant activity during soaking of sorghum grains were determined.Results:Total phenols,total flavonoids,tannins,vitamin E,P-carotene and antioxidant activity in raw sorghum were ranged from 109.21 to 116.70,45.91 to 54.69,1.39 to 21.79 mg/100 g,1.74 to 5.25,0.54 to 1.19 mg/kg and 21.72%to 27.69%and 25.29%to 31.97%,respectively. The above measured compounds were significantly decreased after soaking.p-Hydroxybenzoic acid,vanillic acid,syringic acid and cinnamic acid represent the major phenolic acids in Dorado variety.While ferulic acid,p-coumaric acid,gallic acid and caffeic acid represent the major phenolic acids in Shandaweel-6.On the other hand,protocatechuic acid represents the major phenolic acids in Giza-15.Regarding flavonoids components,Dorado was the highest variety in kampferol and naringenin while Shandaweel-6 was the highest variety in luteolin, apigenin,hypersoid,quercelin and christen.Finally,Giza-15 was the highest variety in catechin. Phenolic acids,flavonoid compounds and antioxidant activities were decreased after soaking. Conclusions:Sorghum varieties have moderate quantities from total phenols,total flavonoids, tannins,phenolic acids compounds,flavonoid components,vitamin E,P-carotene and antioxidant activity which decreased after soaking. 展开更多
关键词 SORGHUM SOAKING Total PHENOLS FLAVONOIDS tanninS Vitamin E Β-CAROTENE Antioxidant activity Phenolic acids Flavonoid components Biochemical change
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