Tree Gum Research Articles

Fabrication of a low surface energy acrylic/melamine clearcoat with enhanced weathering and biological resistances: Investigation of the role of organic UV absorber and nanosilica particles

Abstract Improvement of the weathering resistance of an acrylic/melamine clearcoat containing surface active additive for achieving proper biological resistance has been considered in this study. For this purpose, organic UV absorber (Hydroxyphenyl-benzotriazole) and inorganic UV blocker (silica nanoparticles) were used separately and in combination in the clearcoat. The coatings properties were evaluated by gonio-spectrophotometry, UV–vis, tensile, contact angle and Fourier transform infrared spectroscopy (FT-IR) tests before and after exposure to weathering condition. Also, the biological resistance of the coatings against simulated tree gum (Arabic gum) was studied before and after aging. Results revealed significant improvement of the coatings resistance against UV degradation using combination of organic UV absorber and silica nanoparticles. The improved weathering resistance of the coatings in the presence of organic UV absorber and nanosilica resulted in the improvement of the coatings biological resistance against Arabic gum.

Evaluating hydrothermal synthesis of fluorapatite nanorods: pH and temperature

ABSTRACTIn this study, the fluorapatite was synthesised by a hydrothermal technique in different pH and temperature using apricot tree gum surfactant. The fluorapatite was synthesised in different shapes such as spherical, Chrysanthemum flower and rod. The effect of two factors (pH and temperature) on the shape and dimension of synthesised fluorapatite was investigated through the full factorial design. An experimental strategy was developed based on the analysis of variance to create mathematical models for the shape and dimension of synthesised fluorapatite. Findings revealed that the pH of hydrothermal solution is more significant factor than temperature in terms of shape and dimension of the synthesised fluorapatite. It was illustrated that similar nanorods structure to the human tooth enamel can be achieved in pH of 10 and temperature of 70 °C The transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDS) spectroscopy were carried out for characterisation of synthesised fluorapatite.

Green Synthesis: Nanoparticles and Nanofibres Based on Tree Gums for Environmental Applications

Abstract The recent advances and potential applications of nanoparticles and nanofibres for energy, water, food, biotechnology, the environment, and medicine have immensely conversed. The present review describes a ‘green’ method for the synthesis and stabilization of nanoparticles and ‘green electrospinning’ both using tree gums (arabic, tragacanth, karaya and kondagogu). Furthermore, this review focuses on the impending applications of both gum stabilized nanoparticles and functionalized membranes in remediation of toxic metals, radioactive effluents, and the adsorptive removal of nanoparticulates from aqueous environments as well as from industrial effluents. Besides, the antibacterial properties of gum derivatives, gum stabilized nanoparticles, and functionalized electrospun nanofibrous membranes will also be highlighted. The functionalities of nanofibrous membranes that can be enhanced by various plasma treatments (oxygen and methane, respectively) will also be emphasized.

Combined therapy using low level laser and chitosan-policaju hydrogel for wound healing

We have evaluated the effect of POLI-CHI hydrogel based on policaju (POLI) from cashew tree (Anacardium occidentale L.) gum and chitosan (CHI), associated or not with Low level laser therapy (LLLT), in wound healing. Sixty male Wistar rats were assigned into four groups: POLI-CHI hydrogel (H); LLLT (L); POLI-CHI with LLLT (HL) and saline control (C). Macroscopic evaluations were carried out using clinical observations and area measurements, as well as microscopic analysis by histological criteria. H and HL presented more esthetical scar tissue and larger wound contraction compared to C. Histopathological analyzes showed: stronger presence of fibrin-leukocyte crust in L and HL at day 3; stronger collagen presence in H, L and HL; weak presence of focal necrosis at 7 and 14days in H; weak neutrophilic exudate in H, L and HL; regression of the vascular neoformation at 7days in H, and modulation of the same in L and HL. These results demonstrated that POLI-CHI contributed to more efficient healing process and modulation of the inflammation; furthermore, the combined use with LLLT subtle potentiated this process.

Application of cashew tree gum on the production and stability of spray-dried fish oil.

Evaluation of cashew gum compared to conventional materials was conducted regarding properties and oxidative stability of spray-dried fish oil. Emulsions produced with cashew gum showed lower viscosity when compared to Arabic gum. The particle size was larger (29.9μm) when cashew gum was used, and the encapsulation efficiency reached 76%, similar to that of modified starch but higher than that for Arabic gum (60%). The oxidation process for the surface oil was conducted and a relative lower formation of oxidation compounds was observed for the cashew gum treatment. GAB model was chosen to describe the moisture adsorption isotherm behaviours. Microparticles produced using Arabic and cashew gums showed greater water adsorption when exposed to higher relative humidities. Microparticles produced using cashew gum were more hygroscopic however encapsulation efficiency were higher and surface oil oxidation were less pronounced. Cashew gum can be further explored as an encapuslant material for spray drying processes.

Novel Biodegradable Cast Film from Cherry Tree Gum, Development, Modification and Characterization

The feasibility of sweet cherry gum as a bio-based film-forming material and effect of hydrogen peroxide as a chemical modifier investigated. The influence of film compositions (gum, glycerol) and hydrogen peroxide on the physical properties of films, including solubility in water, permeability to water vapor (WVP), mechanical properties, and transparency, thermal and microstructural properties evaluated. The results showed that WVP and thickness increased by gum and glycerol concentration, but significantly decreased by hydrogen peroxide. As expected, elongation-at-break and solubility, increased at higher concentration of glycerol but the tensile strength decreased at the same condition. The film transparency was influenced by the dry weight content and was improved by higher concentrations of hydrogen peroxide. The partial degradation of polymer chain by hydrogen peroxide was observed by FTIR analysis.

Studies on Electrical, Thermal and Corrosion Behaviour of Cashew Tree Gum Grafted Poly(Acrylamide)

The present work aimed to study the thermal transitions, electrical properties and corrosion behaviour of cashew tree gum (CTG), poly (acrylamide) (PAM) and cashew tree gum grafted poly (acrylamide) (CTG-g-PAM) copolymer. Various amounts of acrylamide monomer were grafted onto cashew gum using a radical polymerization method. The formation of graft copolymer was analysed by FTIR, UV, SEM, DSC and electrical conductivity measurements. The FTIR and UV spectrum infers the occurrence of strong intermolecular interaction between cashew gum and poly (acrylamide). SEM photographs revealed that the acrylamide unit was well inserted into the cashew gum segments. The DSC analysis showed a significant decrease in glass transition temperature with an increase in amount of acrylamide chains. CTG shows higher AC conductivity than PAM and the conductivity of graft copolymer increases with the concentration of acrylamide up to certain concentration of monomer and thereafter the value decreases. The dielectric properties such as dielectric constant and dielectric loss tangent values of PAM was lower than CTG and the dielectric values also shows a similar trend as AC conductivity. CTG, PAM and its graft copolymer with various amount of poly (acrylamide) have been investigated as a corrosion inhibition for mild steel in hydrochloric acid. The inhibition efficiency increased with increase in concentration of PAM in the graft copolymer. PAM was found to have the high inhibition efficiency than CTG, due to the difference in their molecular structures. The corrosion rate of all the samples enhanced with the raise in temperature whereas the inhibition efficiency deceases.

Cashew gum-chitosan blended films: Spectral, mechanical and surface wetting evaluations

Blends of cashew tree gum with chitosan and glycerol as plasticizer were prepared by casting and characterized by Fourier transform infrared spectroscopy (FTIR), mechanical (DMA) and thermogravimetric analysis (TG), scanning electron microscopy (SEM) and surface wettability by static contact angle measurements. FTIR analysis confirmed the consolidation of both polysaccharides and revealed a clearly interaction between the glycerol molecules and hydroxyl groups of chitosan. Chitosan and glycerol improved films mechanical properties and interferes on surface wettability. The unblended cashew gum films presented hydrophilic surfaces (medium measure angle as 40o) and with the addition of chitosan provides a shift towards a more hydrophobic behavior (52o and 75o for additions of 0.5% and 1.0% (w/w) chitosan respectively). Microscopy surface observation confirmed that the presence of glycerol reduced film cracking, changing them from fragile to a more plastic property. The film forming ability of chitosan is also preserved when blending with cashew gum.

New evidences on efficacy of boronic acid-based derivatization method to identify sugars in plant material by gas chromatography–mass spectrometry

This work presents an analytical procedure based on gas chromatography–mass spectrometry which allows the determination of aldoses (glucose, mannose, galactose, arabinose, xylose, fucose, rhamnose) and chetoses (fructose) in plant material.One peak for each target carbohydrate was obtained by using an efficient derivatization employing methylboronic acid and acetic anhydride sequentially, whereas the baseline separation of the analytes was accomplished using an ionic liquid capillary column. First, the proposed method was optimized and validated. Successively, it was applied to identify the carbohydrates present in plant material. Finally, the procedure was successfully applied to samples from a XVII century painting, thus highlighting the occurrence of starch glue and fruit tree gum as polysaccharide materials.

Modulating Effects of Arabinogalactans from Plant Gum Exudates on Human Complement System

Gum arabic and cashew nut tree gum exudate polysaccharide (CNTG) are plant polysaccharides composed of galactose and arabinose known as arabinogalactans (AGs). Although these fractions are used in food and pharmaceutical industry, cases of allergic reactions were described in clinical reports. As AGs were reported as modulators of the classical (CP) and alternative pathways (AP) of complement system (CS), in the present work, we investigate whether gum arabic and CNTG have an effect on both CS pathways. The complement fixation tests were performed with (CP-30 and AP-30) and without pre-incubation (CP-0 and AP-0). For CP-30, CNTG and gum arabic (833μg/ml) showed a reduction of 28.0% (P=0.000174) and 48.5% (P=0.000143), respectively, on CP-induced haemolysis. However, no effect was observed for CP-0 in the CP-induced haemolysis. For AP-30, both CNTG and gum arabic (833μg/ml) showed 87% reduction on the CP-induced haemolysis, with IC50 values of 100 and 7μg/ml, respectively. For AP-0, a reduction of 11.3% for gum arabic and no effect for the CNTG on the CP-induced haemolysis were observed. These results suggested that gum arabic and CNTG could be acting as activators of the CS. Thus, this effect on the CS, especially on the AP, which accounts for up to 80-90% of total CS activation, indicates that both fractions may be harmful because of their potential pro-inflammatory action. Considering that CS activation induces inflammatory response, further studies confirming this immunomodulatory effect of these fractions are required to insure their safe use.

Carob tree gum impact on the properties and quality of wheat bread

Carob tree gum impact on the properties and quality of wheat bread

Prunus × yedoensis tree gum mediated synthesis of platinum nanoparticles with antifungal activity against phytopathogens

Green synthesis of platinum nanoparticles (PtNPs) using Prunus × yedoensis tree gum extract was studied. Color changes, ultraviolet–visible spectra (277nm), X-ray diffraction peaks (2θ=38.17, 45.54, and 68.12), and Fourier transform infrared spectroscopy confirmed the presence of PtNPs. Transmission electron microscopy shows that PtNPs are mostly spherical and oval in shape, with an average particle size of 10–50nm. Chemical constituents present in the gum extract may be responsible for the reduction of Pt ion. Among the five phytopathogens tested, the two pathogens Colletotrichum acutatum and Cladosporium fulvum show 15mm and 18mm zones of inhibition against synthesized PtNPs at 4 and 8μg/well, respectively.

Fabrication and characterization of biopolymer nanocomposites from natural resource materials

In this study, nanocomposites of cashew tree gum (CTG) encapsulated nano‐magnetite (Fe3O4) was prepared and characterized by FTIR, UV–visible, X‐ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), magnetic and conductivity measurements. The characteristic absorption peaks in FTIR and UV–vis spectra of CTG was found to be shifted to higher wave numbers in CTG/Fe3O4 composite, which is due to the intermolecular interaction between nanoparticles and the CTG. The XRD patterns indicated that amorphous region of gum was decreased by the addition of metal oxide nanoparticles. SEM images show that nano‐Fe3O4 was uniformly dispersed in the cashew gum segments. DSC analysis revealed that the glass transition temperature and melting behavior of composites were higher than those of the pure gum. TGA results indicated that the thermal decomposition temperature of the composite increases with the increase in concentration of metal oxide nanoparticles. The magnetic properties studied by a vibrating sample magnetometer indicate that electromagnetism of CTG/Fe3O4 nanocomposites were superparamagnetic. The values of saturation of magnetization (Ms) and remanence (Mr) increases, while the coercivity (Hc) decreased with increase in Fe3O4 content in the composite. The AC electrical conductivity of the nanocomposites was significantly increased with the increase in Fe3O4 content in the nanocomposite. Due to the ordered structure of polymer composite, the dielectric constant and dielectric loss tangent (tan δ) of nanocomposites were also increased with increase in the concentration of nanoparticles. POLYM. COMPOS., 38:E66–E73, 2017. © 2016 Society of Plastics Engineers

Evaluation of degradability of two polyurethane refinish coatings against biological materials: A case study

Abstract In this study the effect of bird droppings and tree gums on two different polyurethane refinish coatings has been investigated. To this end, Arabic gum and pancreatin were used as simulated tree gum and bird dropping, respectively. These substances were applied on coatings exposed to UV radiation and moisture for different exposure times. Various techniques were used to study the appearance of the degraded coatings. Structural analysis of samples was done by FTIR spectroscopy. Surface free energy and thermo mechanical characteristics of refinish coatings were studied by contact angle measurement and DMTA respectively. All experiments were carried out before and after degradation process. In general, it was revealed that while pancreatin degraded the coatings chemically, Arabic gum affected it mechanically and chemically, leading to wrinkle-like deformations on the coating surface. It was also concluded that the cross-linking density and surface free energy have vital roles in the degradation of automotive refinish coatings. It was demonstrated that low cross-linking density and Tg of polyurethane system created a dynamic system which can be post-cured during experiment, leading to enhanced biological resistance. According to this finding, it was also revealed that coating history before bio attack is an important factor in the biological performance of polyurethane systems.

Multifunctional ternary composites of poly (vinyl alcohol)/cashew tree gum/pumice particles

Polymer blend composite based on poly(vinyl alcohol) (PVA)/cashew tree gum (CTG)/with various content of pumice particles were prepared and characterised by FTIR, UV, XRD, SEM, DSC, impedance analyzer, and biodegradation studies. Spectroscopic analysis revealed that the addition of pumice particles to the blend causes structural variation in the PVA/CTG network. The XRD patterns indicated that amorphous domains of the blend decreased with increase in the pumice content. SEM revealed that the pumice particles were well distributed in the blend matrix. DSC studies showed that both the glass transition and melting temperature of the composites increases due to the intermolecular interaction between pumice particles and blend phases. Blend composite with 10 wt% of sample shows higher conductivity and dielectric properties than the pure blend is due to the increase in orderness of the pumice particles inside the polymer chain. When the loading of pumice was increased above 10 wt%, the electrical properties of the composite decreased, which is due to the agglomeration of filler particle in the polymer matrix. The composite undergoes slow biodegradation than the pure blend. POLYM. COMPOS., 39:38–45, 2018. © 2016 Society of Plastics Engineers

Natural Polymer of Iraqi Apricot Tree Gum as a Novel Corrosion Inhibitor for Mild Steel in 1 M HCl Solution

Corrosion inhibition of mild steel in 1 M hydrochloric acid using Iraqi apricot tree gum Arabic as natural polymer was studied. The weight loss method was used to predict the efficiency of the inhibitor on corrosion of mild steel in a temperature range of 17–40°C. The FTIR result of natural polymer revealed that the C=O and O-H groups were found in the structure of the natural polymer. The results of weight loss method showed that the inhibition efficiency (I%) increased with the increase in both the natural polymer concentration and the temperature; therefore, chemical adsorption mechanism was suggested in this system. The different mathematical models of the adsorption isotherms were studied and the results revealed that natural polymer was found to obey Temkin, Langmuir, and Freundlich adsorption isotherm. The activation energy of adsorption, enthalpy of adsorption, and entropy of adsorption were obtained for different concentrations of natural polymer (0, 0.1, 0.2, and 0.3 g/L) and the results showed that the thermodynamic properties decreased with the loading of a natural polymer. Gibbs free energy of adsorption results was a minus value that led to the conclusion of the spontaneous adsorption of the natural polymer in this system.

Green synthesis of silver nanoneedles using shallot and apricot tree gum

A green synthesis method to produce silver nanoneedles was described using shallot and apricot tree gum (ATG). A fast, simple, and low cost method was used to synthesize silver with nanoparticle and nanoneedle shape from the silver nitrate solution. Shallot as a reducing agent and apricot tree gum (ATG) as a stabilizer and a capping agent were utilized to reduce and form silver ions into silver atoms with needle and particle shape. Moreover, high crystalline structures of silver nanoparticles (AgNPs) with diameters of 8–20 nm and silver nanoneedles with average diameters of 50–60 nm and lengths of 5–10 μm were consequently synthesized by shallot and the mixture of shallot and ATG. A self-assembly mechanism was proposed to indicate the formation of needle-like structures of spherical AgNPs via carbon chains of ATG. The results indicate that the presence of ATG with shallot can transfer the reduced AgNPs into the silver nanoneedle. The findings were characterized using X-ray diffraction (XRD), ultra violet visible (UV-Vis) spectrometry, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) techniques.

The organic materials in the Five Northern Provinces’ Assembly Hall: disclosing the painting technique of the Qing dynasty painters in civil buildings

The beiwusheng huiguan (‘Meeting hall of the Five Northern Dynasties’) is a building complex from the Qing dynasty (1636–1912 ad) located in Wafangdian, near Ziyang, in the south of the Chinese Province of Shaanxi. Two of the preserved halls are richly decorated with wall paintings dated probably in 1848 ad and representing scenes of the ‘Romance of the Three Kingdoms’ and Confucian moral tales. They are a rare example of well-preserved mural paintings of high artistic value inside civil buildings. The aims of this paper are the chemical characterization and localization of organic materials used as binders and colorants in the wall paintings. A multi-analytical approach, consisting in the combined use of gas chromatographic–mass spectrometric techniques (GC/MS and Py-GC/MS) and high-pressure liquid chromatography with diode array detector (HPLC–DAD), was chosen for these purposes. Proteinaceous materials (animal glue and egg), saccharide material (fruit tree gum) and a siccative oil were identified in different paint layers supplying invaluable information about the painting technique used. Moreover, the analyses of organic dyes allowed identifying indigo and gallic acid in more than one sample adding fundamental information about Chinese artists’ techniques in mural paintings, missing from the previous studies. To shed light on the gilding technique, the distribution of the painting materials was achieved by means of synchrotron radiation Fourier transform infrared spectroscopy (SR micro-FTIR) and X-ray fluorescence (SR micro-XRF). The results obtained from the multi-analytical approach enabled us to determine the organic materials both binders and organic colorants used by Chinese artisans, highlighting the high technical level achieved in nineteenth century. The binding media and the organic colorants identified, as well as their distribution, allowed the discussion on the painting technique used by the artists of the Qing dynasty giving information for the first time about the decoration of Chinese civil buildings.

Fluoridated hydroxyapatite nanorods as novel fillers for improving mechanical properties of dental composite: Synthesis and application

Abstract Fluoridated hydroxyapatite (FHA) in nanorod morphology and hexagonal cross section were synthesised via hydrothermal process using Apricot Tree Gum (ATG) as a surfactant. The synthesised FHA nanorods were then used as reinforcement in bisphenol A-glycol dimethacrylate (Bis-GMA) as base monomer of composite matrix. The FHA nanorods with different ratios were incorporated in the matrix to examine fluoride ion release and pH changes in the Simulated Body Fluid (SBF) and their mechanical properties. The resin without FHA reinforcement was used as the control sample. The Diametral Tensile Strength (DTS), Flexural Strength (FS), and Flexural Modulus (FM) of the reinforced composite were found to be higher compared to the control sample; the values increased from 34.8 to 45.4 MPa, 76.5 to 99.4 MPa, and 1.7 to 2.5 GPa, respectively. Moreover, findings revealed that the pH is reduced by releasing the fluoride ions into the SBF which can be effective for preventing secondary caries. The most optimum mechanical properties were achieved with 0.2 wt% of FHA reinforcement. The FHA nanocomposite meets the minimum standard requirements for dental applications and compared to other dental composites has advantage of preventing formation of secondary caries due to release of fluoride.

Effect of dynamic high pressure on technological properties of cashew tree gum (Anacardium occidentale L.)

Dynamic high pressure (DHP) appears to be an alternative approach to physical modification of polysaccharides aimed improving their technological properties. Therefore, its effect on the functional properties of polysaccharides (i.e., oil absorption capacity, emulsifier, and rheology) needs to be investigated. Cashew tree gum (CG) is a biological macromolecule that has been proposed to be used as an emulsifier in beverage emulsions. To the best of our knowledge, none of the articles in the literature investigates the effect of DHP on the CG properties. This work presents a study on the evaluation of the effects of DHP on functional characteristics of CG, including rheological properties, molecular weight, glycosyl-linkage analysis, solubility, swelling and oil absorption capacity (OAC). The results suggest that DHP is able to modify the technological properties of cashew tree gum (increasing solubility and decreasing apparent viscosity).