Mimosa Tannin Extract Research Articles

Effect of Tannin Furanic Polymer in Comparison to Its Mimosa Tannin Extract on the Growth of Bacteria and White-Rot Fungi.

Tannins are well-known to protect plants from bacteria and fungi, but nothing is known about its effects on microorganisms once they are copolymerized. Therefore, a study was conducted to evaluate the effect of a tannin−furanic polymer in comparison with industrial mimosa tannin extract on the in vitro growth of two strains of bacteria, Bacillaceae and Pseudomanadaceae, and two white-rot fungi, Trametes versicolor and Agrocybe aegerita. Results have highlighted that the tannin polymer did not inhibit the growth of tested bacteria and even favored the growth of Bacillaceae without extra glucose. The growth of both fungi was enhanced by mimosa tannin and its polymer at low concentrations (<1%), while concentrations above 10% had a growth-inhibiting effect, which was slightly less strong for the polymer compared to the tannin against Trametes versicolor. These findings highlighted that tannin−furanic polymers can be tolerated by certain microorganisms at low concentration and that their inhibitory effect is similar or slightly lower than that of the pristine tannin extract.

Preparation and properties of a novel type of tannin-based wood adhesive

ABSTRACT A novel biomass-based wood adhesive was prepared with commercial Mimosa tannin extract and glycerol diglycidyl ether (GDE) by convenient mechanical mixing. GDE served as the crosslinker of the tannin without any aldehyde addition yielding hardened three-dimensional networks. Different weight ratios of tannin/GDE were investigated by a number of techniques to determine their influence on final properties. The results showed that a non-hydrolysable ester bonds can be formed between the epoxy groups of GDE and hydroxyl groups of tannin, this being the critical factor for the good water resistance obtained by the wood adhesives prepared. Moreover, the dry and wet shear strength exhibit positive correlation with the proportion of GDE added. Even at a relatively small proportion of GDE (33% of the weight of dry tannin), the dry and 24 h cold water shear strengths of the bonded plywood satisfied the requirements of relevant standard (GB/T 9846–2015, ≥0.7 MPa). The thermal stability of the tannin-based wood adhesive so prepared progressively improved with the increasing proportion of GDE.

Polycondensation Resins by Flavonoid Tannins Reaction with Amines.

Reaction of a condensed flavonoid tannin, namely mimosa tannin extract with a hexamethylene diamine, has been investigated. For that purpose, catechin was also used as a flavonoid model compound and treated in similar conditions. Solid-state cross-polarisation/magic-angle spinning (CP-MAS) carbon 13 nuclear magnetic resonance (13C NMR) and matrix assisted laser desorption ionisation time of flight (MALDI-ToF) mass spectroscopy studies revealed that polycondensation compounds leading to resins were obtained by the reaction of the amines with the phenolic hydroxy groups of the tannin. Simultaneously, a second reaction leading to the formation of ionic bonds between the two groups occurred. These new reactions have been shown to clearly lead to the reaction of several phenolic hydroxyl groups, and flavonoid unit oligomerisation, to form hardened resins.

Soy-based, tannin-modified plywood adhesives

ABSTRACT In this research, two different types of commercial tannins, namely a hydrolysable tannin (chestnut) and a condensed flavonoid tannin (mimosa), were used to prepare two types of soy-based (soy flour (SF) and soy protein isolate) adhesives for making plywood. Thermogravimetric properties (TGA) and its derivative as function of temperature (DTG) of different soy-based adhesive were measured in the range 40°C–300°C. Thermomechanical analysis (TMA) from 25°C to 250°C was done for the different resin formulations. Duplicate three-ply laboratory plywood panels were prepared by adding 300 g/m2 of the adhesives’ total resin solid content composed of SF or isolated soy protein (ISP), urea, chestnut, and mimosa tannin extracts with hexamine as hardener. Based on the results obtained, tannins can improve SF adhesion properties. The TMA showed that chestnut tannin extract appeared to react well with SF, while mimosa tannin extract appeared to react well with ISP. Matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry also showed that among other reactions, the soy protein amino acids reacted with the tannins. Furthermore, delamination and shear strength test results showed the good water resistance of plywood bonded with soy-based tannin modified adhesive.

Feasibility Study on the Production of Particleboard from Maize Cobs, Rice Husks, and Groundnut Shells Using Acacia Mimosa Tannin Extract as the Bonding Adhesive

AbstractIn recent years, depleted resources and environmental concerns have stimulated research in renewable and recyclable materials for particleboard production. This paper presents the research work on the production of particleboards using maize (Zea mays) cobs, rice (Oryza glaberrima) husks, and groundnut (Arachis hypogaea) shells, which are abundantly available as agricultural residues. The goal of this project was to study the feasibility of medium-density particleboard panels made of agricultural residues for use as internal partition wall cladding in residential buildings. The panels of densities between 600 and 900 kg/m3 were produced using a natural-based adhesive from acacia mimosa tannin extract and hexamine. Some other parameters like the moisture content (after adhesive application) and the press temperature were varied during the production so as to investigate their effect on some mechanical and physical properties like internal bond strength, bending modulus of rupture, swelling, and har...

Reaction of condensed tannins with ammonia

Reaction of condensed (flavonoid) mimosa tannin extracts with concentrated aqueous ammonia has been investigated. For that purpose, catechin was also used as a flavonoid model compound and treated in similar conditions. Solid state CP-MAS 13C NMR and MALDI-ToF spectroscopy studies revealed that, unlike what was recently theorised, amination is not always regioselective and leading to the conversion of one single OH group in C4′ into NH2. In the present study, new reactions have been evidenced, clearly leading to multiamination of several phenolic hydroxyl groups, heterocycle opening, and oligomerisation and cross-linking through the formation of N bridges between flavonoid units.

Cornstarch–mimosa tannin–urea formaldehyde resins as adhesives in the particleboard production

AbstractThe objective of this work was to demonstrate the utilisation of cornstarch–mimosa tannin‐based resins designed for application as an adhesive in particleboard production. Bond qualities of cornstarch–mimosa tannin–urea formaldehyde (UF) resins and commercial UF resin were assessed by using an automatic bonding evaluation system, prior to production of particleboards panels. In order to evaluate the quality of cornstarch–mimosa tannin–UF resins, particleboards were produced and physical and mechanical properties were investigated. These physical properties included rheological, thermogravimetric analysis and solid phase 13C NMR analysis of resins. Internal bond, surface soundness, thickness swelling, porosity, modulus of rupture and modulus of elasticity mechanical properties of particleboards bonded with cornstarch–mimosa tannin–UF resins were also determined.The results showed that it is possible to add cornstarch and mimosa tannin, respectively, up to 10 and 4% to the UF resin without to alter the physical and mechanical properties of the boards. The performance of these panels is comparable to those of boards made using commercial UF resin. Petrochemical UF resins could be partially substituted in industrial applications by addition of cornstarch and mimosa tannin extracts.

Derivatives of biomacromolecules as stabilizers of aqueous alumina suspensions

AbstractThe stabilization of alumina suspensions is key to the development of high‐performance materials for the ceramic industry, which has motivated extensive research into synthetic polymers used as stabilizers. In this study, mimosa tannin extract and a chitosan derivative, that is, macromolecules obtained from renewable resources, are shown to be promising to replace synthetic polymers, yielding less viscous suspensions with smaller particles and greater fluidity, that is, more homogeneous suspensions that may lead to better‐quality products. The functional groups of tannin present in mimosa extract and N,N,N‐trimethylchitosan (TMC) are capable of establishing interactions with the alumina surface, thus leading to repulsion between the particles mainly due to steric and electrosteric mechanisms, respectively. The stabilization of the suspension induced by either TMC or mimosa tannin was confirmed by a considerable decrease in viscosity and average particle size, in comparison with alumina suspensions without stabilizing agents. The viscosity/average particle size decreased by 49/84% and 52/87% for suspensions with TMC and mimosa tannin, respectively. In addition, the increase in the absolute zeta potential upon addition of either TMC or mimosa tannin extract, especially at high pHs, points to an increased stability of the suspension. The feasibility of using derivatives of macromolecules from renewable sources to stabilize aqueous alumina suspensions was therefore demonstrated. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Processing conditions analysis of Eucalyptus globulus plywood bonded with resol-tannin adhesives

Phenol-formaldehyde resol containing mimosa tannin extract was employed to produce plywood panels with two plies from Eucalyptus globulus veneers. The effect of processing conditions and tannin content on the gelation time of the adhesive in the glue line was evaluated by dynamic-mechanical analysis (DMA). These results were related with shear strength and wood failure of glue line in the final panels. Hazardous petrochemical phenol could be partially substituted in resols in industrial applications by addition of mimosa tannin extracts.

Adsorption of Organic Anions on Low-Carbon Steel in Saturated Ca ( OH ) 2 and the HSAB Principle

This paper represents a fundamental study of corrosion inhibition behavior of selected organic anions on low-carbon steel in saturated solution containing chlorides. The compounds studied include eight amino acids, two carboxylic acids, ascorbic acid and a mimosa tannin extract. All the inhibitors suppressed the reduction of , a process that is known to be strongly catalyzed on passive iron, the essential step being reaction with Fe(II) surface sites. The proposed mechanism of inhibition involves formation of surface chelates which tend to stabilize iron in Fe(III) state and increase the Tafel slope of the actual potential dependence of the [Fe(II)] surface centers. In accordance with the hard and soft acid and base principle, the corrosion inhibition effect was well correlated with the absolute electronegativity of the anions obtained from the semiempirical quantum molecular modeling calculations. The lack of correlation of the inhibition effect with the absolute hardness of the inhibitor anions has been explained by considering the charge of the anions as the companion parameter for absolute hardness. The highest degree of inhibition was observed for ascorbic acid that also showed a clearly pronounced increase in the pitting initiation potential.

Effect of Tannins on the In Vitro Growth of Escherichia coli O157:H7 and In Vivo Growth of Generic Escherichia coli Excreted from Steers

The effect of commercially available chestnut and mimosa tannins in vitro (experiment 1) or in vivo (experiment 2) on the growth or recovery of Escherichia coli O157:H7 or generic fecal E. coli was evaluated. In experiment 1, the mean growth rate of E. coli O157:H7, determined via the measurement of optical density at 600nm during anaerobic culture in tryptic soy broth at 37°C, was reduced (P < 0.05) with as little as 400 μg of either tannin extract per ml of culture fluid. The addition of 200, 400, 600, 800, and 1,200 μg of tannins per ml significantly (P < 0.01) reduced the specific bacterial growth rate when compared with the nontannin control. The specific growth rate decreased with increasing dose levels up to 800 μg of tannins per ml. Bacterial growth inhibition effects in chestnut tannins were less pronounced than in mimosa tannins. Chestnut tannin extract addition ranged from 0 to 1,200 μg/ml, and a linear effect (P < 0.05) was observed in cultures incubated for 6 h against the recovery of viable cells, determined via the plating of each strain onto MacConkey agar, of E. coli O157:H7 strains 933 and 86-24, but not against strain 6058. Similar tests with mimosa tannin extract showed a linear effect (P < 0.05) against the recovery of E. coli O157:H7 strain 933 only. The bactericidal effect observed in cultures incubated for 24 h with the tannin preparations was similar, although it was less than that observed from cultures incubated for 6 h. When chestnut tannins (15 g of tannins per day) were infused intraruminally to steers fed a Bermuda grass hay diet in experiment 2, fecal E. coli shedding was lower on days 3 (P < 0.03), 12 (P = 0.08), and 15 (P < 0.001) when compared with animals that were fed a similar diet without tannin supplementation. It was concluded that dietary levels and sources of tannins potentially reduce the shedding of E. coli from the gastrointestinal tract.

Synthesis and characterization of phenolic novolacs modified by chestnut and mimosa tannin extracts

AbstractThe possibility of reacting chestnut and mimosa tannins with the intermediates of the synthesis reaction for phenolic novolacs under acid conditions has been proved using differential scanning calorimetry (DSC). The amount of intermediate compounds and the percentage of free phenol and formaldehyde in the reaction mixture is decisive for the determination of the stage in which the addition of tannin is suitable. Synthesis of novolac resins modified with 14 wt % mimosa tannin extract or with several percentages (until 40 wt %) of chestnut tannin have been performed. The reaction pathways have been investigated by DSC, fourier transformed infrared spectroscopy and gel permeation chromatography. Ester groups of chestnut tannin result in a reaction pathway different from the one for mimosa‐modified resins and nonmodified resins. Preliminary studies of curing reactions of synthesized resins with hexamethylenetetramine indicate that the cure of modified‐resins is even more favorable than the one for nonmodified resins. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4412–4419, 2006

Rheology of polyflavonoid tannin–Formaldehyde reactions before and after gelling. I. Methods

AbstractThe gelling and hardening reactions of different, commercial polyflavonoid tannin extracts of the prorobitenedin/profisetinidin, procyanidin, and prodelphinidin types with formaldehyde were studied by parallel‐plate rheometry. To do this, methods to determine the rheological characteristics of tannin–formaldehyde polycondensation reactions both before and after the gel point were developed. The validity of some modifications of known methods was checked on the best‐known commercial tannin extract, namely, the reaction of the mimosa tannin extract with 5% paraformaldehyde, over a range of different temperatures. The gel point was determined by three different methods, namely, by the crossover point of viscous and elastic moduli, by the extrapolation to ∞ of the zero‐frequency viscosity, and by determining the point at which the value of tan δ is constant whatever frequency is used in the measurement. The results obtained were critically compared. The comparisons obtained were good and were reproducible when the first two methods were used, but not when the third one was used. This allowed the determination of the energy of activation at different stages in the tannin–aldehyde polycondensation reaction and the calculation of the degree of conversion of the tannin–aldehyde polycondensation before, at, and after the gel point. Mathematical expressions defining the degree of conversion for tannin–aldehyde reactions before, at, and after the gel point as a function of different moduli were developed and checked with the experimental data obtained. Methods and mathematical expressions for the determination of the rate constants of the different stages of the reaction were also developed and checked. After the gel point, the system was modeled using both a diffusion‐controlled model and a second‐order kinetic law. The applied results obtained indicated that, although a certain element of diffusion control is present, a second order, diffusion‐independent kinetic is more valid under the experimental conditions used. This indicates that the rheometry approach to a polycondensation network is limited mostly by the capability of the equipment to the region after the gel point, where diffusion control does not as yet play a predominant role. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 852–863, 2002

Urea–resorcinol–formaldehyde adhesives of low resorcinol content

AbstractLow resorcinol content cold‐setting urea–resorcinol–formaldehyde (URF) resins were prepared. Most of these adhesives had water‐resistant properties, whereas some also presented weather‐ and boil‐proof adhesive characteristics and performance. URF resins of acceptable adhesive performance were also prepared by inducing branching by introducing a certain amount of resorcinol or of polyflavonoid mimosa tannin extract as a branching unit. Resorcinol content as low as 12.7 and 12.15% on total liquid resin were obtained by this method while still maintaining adhesive performance and water‐resistant properties. © 1993 John Wiley &amp; Sons, Inc.

Évaluation de la dégradation de deux types de tanin condensé par des bactéries isolées d'écorces en décomposition

Forty-eight bacterial strains isolated from decaying bark were cultivated in a mineral medium with added quebracho and mimosa tannin extracts as carbon sources. The degradation of the two condensed tannins by each bacterial strain was compared by means of two dosage methods permitting estimations of the astringent capacity losses and the attack of the flavane-3-ols groups. For an even incubation period, tannin from mimosa was more strongly degraded than that from quebracho, and depolymerization was much more important than the attack of monomeric structures. These results confirmed the aptitude of those bacteria to degrade condensed tannins, and thus practical utilisation can be foreseen for such strains.[Translated by the journal]