Tung Oil Research Articles

Evaluation of corrosion inhibition and self healing capabilities of nanoclay and tung oil microencapsulated epoxy coatings on rebars in concrete

Corrosion of civil infrastructure is the biggest challenge faced by the construction industry worldwide and billions of dollars are spent for its repair and rehabilitation. One of the methods to mitigate the effects of corrosion is the use of Epoxy Coated Rebars (ECR) in concrete. But epoxy coatings are inherently brittle and susceptible to crack initiation and propagation. Thus, to further improve their efficiency in inhibiting corrosion, modifications in the epoxy coatings have to be done. In the present study, it is suggested to modify epoxy coatings by adding nano-clay and tung oil microcapsules. To measure the effectiveness of these coatings to corrosion inhibition, non-destructive monitoring has been done using electrochemical current measurements and ultrasonic guided wave propagation characteristics while the coated rebars are subjected to impressed current accelerated corrosion. The corrosion introduces non-uniform and localized pits in the rebars and disturbs the path of the propagating guided waves through it by mode conversions and scattering which results in drop in transmitted guided wave signal strengths. Nano dispersion of clay in epoxy not only increase of toughness, tensile and flexural properties of the epoxy but leads to torturing of the path for moisture progression. Lastly, the hydrophobic nature of modified clays will aid in reducing progression of water molecules. This was successfully illustrated by very small corrosion current values and small rate of drop in ultrasonic guided wave voltage signals as compared to plain epoxy coated rebars. On the other hand, tung oil microcapsules in Urea-formaldehyde (UF) shells prepared by in-situ polymerization improves the self-healing ability and adhesion strength of capsule embedded coatings and act as self-healing agents. Tung-oil micro-encapsulated coatings perform the best in terms to corrosion resistance as well as bonding with surrounding concrete. The drop in voltage amplitudes as well as the rate of voltage drop with increasing corrosion exposure is very nominal and insignificant. It points towards remarkable inhibition of corrosion offered by self-healing tung oil microcapsules to corrosion damage.

Superhydrophobic coatings on wood made of plant oil and natural wax

Protection against wetting is a central issue in the finishing of wood, since water promotes degradation and reduced service life of the material. Ideally, wood finishes should provide efficient protection from water while at the same time preserving the overall bio-based character of the material. In order to meet this challenge, we propose a facile way to achieve superhydrophobic coatings on wood by using environmentally benign and even food-safe materials only. Spruce wood samples were dip-coated in a mixture of tung oil and natural beeswax, followed by the deposition of micronized sodium chloride particles. After a washing procedure, EDX confirmed that no sodium chloride remained at the surface. SEM-imaging illustrated the successful formation of a micro-structured topography endowing the surface with water repellence as indicated by stable static water contact angles above 160°. It is thus demonstrated that fully bio-based superhydrophobic wood coatings may be achieved using templating with water-soluble salt.

Copolymers of xylan-derived furfuryl alcohol and natural oligomeric tung oil derivatives

The utilization of vegetable oils as biological oligomers for the synthesis of macromolecular materials has considerably evolved in the last decades, opening the way for the preparation of sophisticated materials based on synthetic processes for the design of polymers with very specific applications. Tung oil (TO), easily obtained from the seeds of the Asian tung tree (Vernicia fordii), is a relatively cheap commodity that has as its main constituent (~85%) a peculiar natural oligomeric triglyceride structure in which each chain bears three conjugated unsaturations corresponding to α-eleostearic acid. Following a previous study based on the association of TO with furans for the preparation of linear and cross-linked structures based on the Diels-Alder click reaction, the present study deals with the cationic (co) polymerization of xylan-derived furfuryl alcohol (FA) with TO, in order to combine the high intrinsic flexibility of the crosslinked TO polymers with the stiffness of the FA resin, which should lead to fully bio-based crosslinked materials with a tunable glass transition. Three approaches were investigated using trifluoroacetic acid (TFA) in chloroform, viz. (i) combining crude TO and furfuryl alcohol, (ii) combining methyl α-eleostearate and furfuryl alcohol, and (iii) polymerizing furfuryl α-eleostearate itself. The polymerization reactions with varying TFA concentrations were followed by 1H NMR spectroscopy, and it was possible to get valuable information on mechanistic aspects. Also, higher concentrations of TFA were used to synthesize and isolate polymer networks, in order to understand their molecular characteristic as well as access their main thermal properties.

A catechol-type lignan and neolignans are specifically present in the seed coat of tung trees

The tung tree produces large seeds with approximately 40–50% of their composition consisting of non-edible oil. α-Eleostearic acid makes up about 80% of tung oil, while linoleic acid and oleic acid make up 7 and 6%, respectively. The oil is readily oxidized due to the three, conjugated double bonds in α-eleostearic acid; however, it is stable inside the tung seed, which is expected to contain strong antioxidative compounds that protect the oil from oxidation. Previously, we isolated and identified a catechol-type lignan (3,3′-bisdemethylpinoresinol) and neolignans (isoamericanol A and americanol A) from the seeds of tung tree fruits that exhibited strong antioxidative activity, similar to that of Trolox. In this study, we show that the catechol-type lignan and neolignans are specifically present in the seed coat of the tung tree fruit seeds. The lignans were not detected in any other tissue, such as the pericarp, bark, leaves, or wood of the tree. The lignan content was determined in each developmental stage of the fruit, and the amount of the three lignans in the tung seeds was the highest in the green mature stage. This was likely because the amount of tung oil was also at its highest during this stage, and the oil composition was stable. Our results indicate that the catechol-type lignan and neolignans are located within the seed coat of the tung tree fruit seeds, where they protect the oil in the endosperm from autoxidation and polymerization processes.

Investigation of Ancient Architectural Painting from the Taidong Tomb in the Western Qing Tombs, Hebei, China

The Taidong Tomb in the imperial tombs of the Qing dynasties has great aesthetic value and a rich history. In this study, we conducted the first investigation ever performed on the raw materials used in the paintings in the Taidong Tomb. Energy dispersive X-ray spectroscopy (EDX), polarized light microscopy (PLM), X-ray diffraction (XRD), micro-Raman spectroscopy (m-RS), Fourier-transform infrared spectroscopy (FTIR) and pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS) were used to comprehensively analyze the painting of Long’en Hall, Xipei Hall and the ceiling of Minglou. In the conclusion of the study, the paintings were found to contain natural mineral and synthetic pigments, including atacamite (Cu2Cl(OH)3), azurite (2CuCO3·Cu(OH)2), vermilion (HgS), carbon black (C), anglesite (PbSO4), white lead (2PbCO3·Pb(OH)2), synthetic emerald green (Cu(CH3COO)2·3Cu(AsO2)2) and ultramarine ((Na,Ca)8(AlSiO4)6(SO4,S,Cl)2). This allows us to conclude that some of the architectural paintings were repainted in the mid-to-late 19th century. The mortar layer may consist of brick ash (albite, gismondine), lime water, tung oil and flour. The fiber layer material may be ramie. Researching the raw materials of the paintings in the Taidong Tomb is of great value because it provides scientific data for the future preservation of the paintings in the tomb.

Preparation and evaluation of corrosion resistance of a self-healing alkyd coating based on microcapsules containing Tung oil

A commercial coating was transformed into a self-healing coating by inserting urea-formaldehyde microcapsules (MCs) containing tung oil (TO), to improve coated metal corrosion resistance. The microcapsules were characterized regarding their morphology and chemical composition, and the presence of tung oil as core material was also proven by FTIR analysis. MCs were then incorporated into the matrix of a commercial mono-component alkyd coating, being added in the same proportion as the corrosion inhibitor (zinc phosphate) present in the original commercial coating. Corrosion resistance was evaluated by the comparison between samples coated with an original commercial coating, commercial coating without zinc phosphate and a commercial coating containing MC., employing a corrosive saline medium of NaCl 3.5 % (w/w), where were carried out the electrochemical analysis of open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS). For this, the stimulus-responsive capacity of microcapsules was proven through mechanical disruption. It was observed that the additive coating presented a satisfactory performance for application in 1020 carbon steel specimens, keeping its properties practically unchanged. The self-healing ability of the coating has been proven and the corrosion protection performance of the coating has been assessed through electrochemical techniques, and the results of the OCP and EIS tests showed that the microcapsules in the coating matrix caused a beneficial increase in barrier properties. Additionally, MC additive coating protected the metallic substrate when it suffers a mechanical defect through the release of the oil and its active protection conditioned to the self-healing effect. Thus, when comparing the types of coatings tested, samples containing MCs of tung oil proved to be a more promising additive than the original additive. Also, a self-responsive stimulus mechanism for this smart coating was proposed based on the blistering caused by the presence of corrosion products.

Characterization and quantitation study of ancient lacquer objects by NIR spectroscopy and THM-Py-GC/MS

Abstract Oils were often used as additives in lacquering process in ancient time, and the proportion of oil to lacquer is crucial for the quality of the lacquer objects. In order to quantitative analyze the proportion of oil to lacquer in the ancient lacquer objects, Near-infrared spectroscopy (NIRS), a non-destructive method was studied. In this research, a partial least squares (PLS) model of reference samples for quantitative analysis of lacquer films was established. When evaluating the final model, factors such as correlation coefficient (R) and the root mean square error of prediction (RMSEP) were considered. The final optimal results of the PLS model showed that RMSEP and correlation coefficients (R) in the calibration set were 0.112 and above 0.98, respectively, demonstrating that NIRS can be used to the quantification analysis of lacquer film. Subsequently the developed PLS model was applied to quantitatively analyze the lacquer samples from the Buddhist statue and altar of Qing dynasty, while thermally assisted hydrolysis–methylation for pyrolysis-gas chromatography-mass spectrometry (THM-Py-GC/MS) was applied for the qualitative analysis. The results show that urushiol-based lacquer and tung oil were used and the ratios of oil in lacquer are varied in different objects for special purposes. For the first time, the proportions of oil to lacquer were revealed in the ancient lacquer objects, which is significant to enhance the knowledge about lacquering techniques in ancient times.

Wood Surface Finishing of Selected Invasive Tree Species

Due to their strong renewal power, the invasive tree species are spreading rapidly, especially in abandoned agricultural and forest areas and along traffic routes and water courses. One way of their restriction is the promotion of their use. In our research, we investigated surface finishing of wood of five selected invasive species in Slovenia, Box elder (Acer negundo L.), Black locust (Robinia pseudoacacia L.), Horse-chestnut (Aesculus hippocastanum L.), Honey locust (Gleditsia triacanthos L.) and Chinese sumac (Ailanthus altissima (Mill.) Swingle), and compared it with the finishing of the European beech (Fagus sylvatica L.) wood. For coatings, we selected one-component waterborne finish on acrylate-polyurethane basis, one-component solventborne finish on polyurethane basis and tung oil as a natural finish. Several surface properties were investigated. We proved that surface hardness, resistance to impact and adhesion were very much related to interactions between the coating and the substrate, while resistance to cold liquids was only dependant on the type of the finish. It was also shown that, in general, finishing of woods of selected invasive tree species was not problematic. The only exception was Black locust wood on which tung oil cured very slowly.

High-pressure densification and hydrophobic coating for enhancing the mechanical properties and dimensional stability of soft poplar wood boards

Effects of high-pressure (HP) treatment on densification of poplar sapwood boards and subsequent coatings were evaluated. Tung oil (TO) and epoxy resin (ER)-coated treatments were used to improve the dimensional stability of HP-densified wood. The density of the wood after HP densification increased from 450 ± 50 kg/m3 for the control to 960 ± 20 kg/m3 at 125 MPa. This process also resulted in the average thickness of HP-densified boards to reduce significantly from 29.7 ± 0.11 mm for the control to 18.8 ± 0.53 mm after HP densification at 25 MPa and 14.3 ± 0.10 mm after 125 MPa treatment for 30 s. The mechanical strength measured as the hardness of densified wood significantly increased from 35% at 25 MPa to 96% at 125 MPa treatment, compared to untreated wood. As expected both TO and ER-coated treatments significantly reduced set-recovery of densified wood when stored at four relative humidity environments. ER showed better anti-swelling performance than TO, and would be a better choice.

On the drying behavior of natural oils used for solid wood finishing

Drying oils provide exquisite bio-based finishes for wood products but their application is restricted by their time-consuming polymerization. Research and industrial development are impeded by a lack of scientific methods to follow the polymerization progress of oils applied on wood. We investigated the drying behavior of linseed oil, tung oil, and their 1:1 mixture both with and without the addition of a drier. Liquid samples revealed faster polymerization of the mainly conjugated and highly unsaturated tung oil than of non-conjugated linseed oil. Recurring water contact angle measurements of oil finishes applied on beech and oak wood showed clear differences in wetting. Tung oil provided hydrophobicity to all wood samples soon after its application, even when used without drier. Linseed oil required longer drying times and was more susceptible to substrate influences but ultimately reached the highest contact angles when equipped with a drier. Further, we observed a relationship between drying time and contact angle stability. As a new and straightforward tool to characterize the drying progress of applied oil-based finishes, we propose the calculation of a contact angle reduction factor, that takes into account both the initial water contact angle as well as its stability over measurement time.

Synthesis and molecular interaction of tung oil‐based anionic waterborne polyurethane dispersion

AbstractIn the present work, four types of anionic waterborne polyurethane dispersions (APUD) based on polytetramethylene ether glycol (PTMG) and two aliphatic diisocyanates, dicyclohexylmethane diisocyanate (HMDI) or isophorone diisocyanate (IPDI), were prepared by polymerization methods which for the first time controlled the location (soft or hard segment) of hydroxylated tung oil (HTO) incorporation into the final APUD. The resulting HTO‐containing APUD polymers (HTO‐APUDs) with postpolymerization crosslinking capability were characterized using FTIR, DMA, AFM and water imbibition methods, and compared to model compounds synthesized to have the same parts of chemical structural linkages for band assignment. A common PUD sample, as well as polypropylene oxide (PPG) with molecular weight similar to HTO (Mn = 400), was used to replace it for preparing control samples to highlight the role of long branched chains and conjugated double bonds in HTO. Based on the analysis of multiple H‐bond interactions, the relationship of HTO location in the APUD polymer structure to the soft/hard segment compatibility and the diisocyanate structure was further studied. This work is expected to provide basic data for properties regulation in practical applications by adjusting the chain and phase structure, as well as the intermolecular interactions, in these APUDs.

Spectroscopic investigation and comprehensive analysis of the polychrome clay sculpture of Hua Yan Temple of the Liao Dynasty.

This article shows the investigation results of the polychrome clay sculptures in Hua Yan Temple of the Liao Dynasty in Datong, China. The mineral pigments, adhesive and painting techniques used in these cultural relics were systematically analyzed in this project. Optical microscope (OM), Scanning electron microscope coupled with an energy-dispersive X-ray spectroscopy (SEM-EDS), micro-Raman, Fourier transform infrared spectrometer (FT-IR) and Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analyses were selected as scientific micro-destructive analytical methods. The results show that the pigments in the polychrome clay sculptures include cinnabar, lead red, malachite, atacamite, azurite, orpiment and gold. Meanwhile, the presence of nitrogen-containing substances and glue-marker characteristic pyrolysis products clearly indicates that the adhesive used in most of the polychrome clay sculptures was glue-protein. Additionally, the combination of heat-bodied tung oil and glue-protein was also found in the golden areas.

Analysis of an Ancient Architectural Painting from the Jiangxue Palace in the Imperial Museum, Beijing, China

The Jiangxue Palace is part of the imperial garden of the Imperial Museum, a world cultural heritage site. In this work, the techniques and components of its color paintings are described and analyzed. The color painting represented a significant architectural component in the Ming and Qing dynasties. This paper analyzes the structure relationship of color painting, morphology, pigment composition, pigment crystal characteristics, and the composition of binder and filler in the plaster by using ultra-depth three-dimensional microscopy, polarized light microscopy, scanning electron microscopy-energy dispersive spectrometry, micro-Raman spectroscopy, X-ray diffraction, Fourier transform infrared spectrometry, and pyrolysis–gas chromatography–mass spectrometry. The Jiangxue Palace paintings are composed of multi-layered structures using pigments such as emerald green, lead white, and lead red (minium). The cross-sections of each structure are composed of a pigment layer (green and white), plaster (albite, anorthite, calcite, tung oil, and flour), and an underlying base of red minium. This research is conducive to a comprehensive understanding of the production technology of the Jiangxue Palace color paintings. The results provide a basis for the subsequent protection and repair of this valuable world cultural heritage site.

In-situ synthesis of synergistically active ceria doped polypyrrole oleo-polyesteramide hybrid nanocomposite coatings: Corrosion protection and flame retardancy behaviour

To overcome the shortcomings of petro-based polymer coatings, researchers have intensified research efforts on the development of eco-friendly and sustainable polymer coatings. It may help in reducing the burden on fossil fuel, which is expected to deplete by near future. Thus, here we report the In-situ formulation of solvent-less hydrophobic bi-functional ceria doped Tung Oil Polyesteramide nanocomposite coatings. The physico-chemical, physico-mechanical, structural, corrosion protective and flame-retardancy performance of these hybrid inorganic-organic nanofillers dispersed Tung Oil polyesteramide nanocomposite coatings were investigated using standard methods i.e. Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), x-ray diffraction (XRD), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vertical burning test (VBT), potentiodynamic polarisation (PDP), electrochemical impedance spectroscopy (EIS) and salt-spray test. The studies revealed that the prepared nanocomposite coatings exhibit excellent adhesion, hydrophobicity, negligible water uptake, superior corrosion protection and flame retardancy behaviour than those of other such reported oleo polymer coating systems. The coatings can be safely used up to 200 °C.

Effects of Pulp Fiber and Epoxidized Tung Oil Content on the Properties of Biocomposites Based on Polylactic Acid

Recently, various environmental-friendly materials have been investigated and developed, especially composites of polylactic acid (PLA) and plant fibers. This paper investigates the effects of pulp fiber (PF) and epoxidized Tung oil (ETO) content on the properties of biocomposites, based on polylactic acid. The bleached pulp fiber reinforced PLA (PLA/PF) composites with 10–50 wt% fiber contents and 0–15% epoxidized Tung oil contents (with a certain number of fiber) were prepared in an internal mixer (Plastograph® EC) at 150 °C. The mechanical properties of PLA/PF composites were improved significantly. The pulp fiber reinforced PLA composites, with the fiber content of 30 wt%, were found to have the highest mechanical properties. The tensile and flexural properties of PLA/Tung oil-soaked-pulp fiber composites were higher than those of PLA/Tung oil unsoaked pulp fiber composites. In addition, the degradation temperature of PLA-based composites decreased after adding more pulp fiber. The pulp fibers were well-dispersed in the PLA matrix with the content up to 30 wt%. The interaction between pulp fiber and PLA matrix improved by the addition of epoxidized Tung oil. Epoxidized Tung oil also improved tensile and flexural strength of composite materials when it was added with a number of below 10% of fiber.

Surveillance of foodborne disease outbreaks in China, 2003–2017

Foodborne disease remains a major public health problem worldwide. To understand the epidemiology and changes of foodborne disease in China, data reported to the National Foodborne Disease Outbreak Surveillance System during 2003–2017 were collected. A total of 19,517 outbreaks, which resulted in 235,754 illnesses, 107,470 hospitalizations, and 1,457 deaths, were reported in this period. Of the 13,307 outbreaks with known etiology, 31.8% of outbreaks were caused by poisonous mushrooms, followed by Vibrio parahaemolyticus (11.3%), saponin (8.0%), Salmonella (6.8%), nitrite (6.4%), pesticide (4.8%), Staphylococcus aureus (4.2%) and Bacillus cereus (3.0%). Among 18,955 outbreaks with reported setting, 46.6% were associated with food prepared in a household, followed by 22.5% with food prepared in a restaurant, and 18.4% prepared in a canteen. Of the 13,305 outbreaks associated with a single food category, fungi (mainly poisonous mushroom) were the most commonly implicated food category, followed by meats, vegetables, aquatic animals, condiments, poisonous plants (such as saponin, tung oil or seed, aconite) and grains (such as rice, noodle, rice noodle). Analysis of foodborne disease outbreaks can provide insight into the most important causative agents and sources of foodborne disease, and assist public health agencies determine the high-risk etiology and food pairs, specific points of contamination and settings to reduce foodborne disease illnesses.

Nano/micro-scale morphologies of semi-interpenetrating poly(ε−caprolactone)/tung oil polymer networks: Isothermal and non−isothermal crystallization kinetics

The isothermal and non-isothermal crystallization kinetics of pure poly(ε−caprolactone) (PCL) and its blends with crosslinked tung oil were investigated as a function of composition, crystallization temperature, and heating rate using differential scanning calorimetric (DSC). The PCL/tung oil semi-interpenetrating polymer networks of different compositions were prepared via cationic polymerization of tung oil in the presence of homogenous solutions of PCL. This unique and relatively new in-situ polymerization and compatibilization blending technique created nano/micro-scale morphologies that cannot be obtained with the traditional melt-processing and/or solvent casting methods. Blends with different miscibility, phase behaviors, and morphologies (miscible, partially miscible, and immiscible) were observed as a function of composition with a constant concentration of boron trifluoride diethyl etherate (BFE) cationic initiator. The morphology of the semi-interpenetrating polymer networks was performed using scanning electron microscopy (SEM). Miscible blends with a single Tg for PCL ≤ 10 wt.%. were observed. While, on the other hand, partially miscible blends with two distinct Tgs and nanoscale morphologies and average particle sizes as small as 100 nm were observed for blends with 20 ≤ PCL wt.% ≤ 30. Immiscible blends with microscale highly interconnected, co-continuous two-phase morphology and two distinct Tgs were detected for 50 wt.% PCL. Both isothermal and non-isothermal crystallization kinetics were strongly influenced by the different miscibility and morphology of the blends. The isothermal and non-isothermal crystallization kinetics of PCL/tung oil blends were analyzed on the basis of Avrami and modified Avrami approaches, respectively. A substantial decrease in the isothermal (longer half time) and non-isothermal (Tm shifted to lower temperature) crystallization kinetics was observed as the concentration of PCL increased in the blends up to 30 wt.% due to the partially miscibility of the blends in this composition range. In a contrast, for 50 wt.% PCL blend, a considerable increase in the crystallization kinetics (isothermal and non-isothermal) was detected due to the highly interconnected, co-continuous two-phase morphology.

Tung oil as an effective modifier for sulfur polymer cement and its performance in galvanic waste encapsulation

The data on the performance of sulfur polymer cement crosslinked with tung oil polymerization modifier are presented. Specimens of sulfur polymer cement (SPC) were prepared with different doses of tung oil in amounts of up to 8.85% of the sulfur mass. The obtained SPCs were used as binders to encapsulate two galvanic wastes differing in their toxic metal composition: waste I and waste II with loadings of approximately 25 and 50% of the composites' mass, respectively. For comparative purposes, appropriate samples of the SPCs and their composites with galvanic wastes were obtained using very similar doses of dicyclopentadiene sulfur modifier. Waste II was also encapsulated using SPC, in which a mixture of tung oil and dicyclopentadiene in a 1:1 weight ratio was used as the modifier. Crosslinking of the tung oil to the SPC matrix was assessed by FT-IR. The obtained SPCs and their composites with galvanic wastes were characterized by SEM and tested for water sorption capacity, compressive strength and metal leaching toxicity using TCLP and EN standards. The effectiveness of the tung oil binding to the SPC network was evidenced by the complete disappearance of methine C–H stretching vibrations at 3010 cm−1 and the double bond –C=C– wagging vibrations at 990 cm−1 in the FT-IR spectrum after processing with sulfur. SEM observations revealed that all the specimens prepared with dicyclopentadiene had a glassy-like fracture surface and also showed fewer cavities and defects in cements and composites when compared to their counterparts prepared with tung oil. The water sorption capacities of all the specimens were below 1%, where the values of those prepared with the tung oil were two to three fold higher than the values of their counterparts prepared with dicyclopentadiene. The pH of the TCLP leachates was in the range of 2.75–2.98, and a decreasing trend in the pH value was found with an increasing modifier dose. The TCLP leachate pH from the waste I monoliths with dicyclopentadiene were generally lower by 0.1–0.35 when compared to the corresponding monoliths with tung oil. The toxic metals immobilization order revealed from the TCLP test (leachate pH around 2.85) is Cd > Sr ≥ Zn > Cu > Ni > Cr > Pb, while the resulting order from the EN test, due to a higher leachate pH of about 5.9, follows Cd > Pb > Zn > Cu ≥ Ni > Sr > Cr. An increased tung oil dose from 2 to 8.85% enhanced the SPC compressive strength by three to four fold, while the same increase of the dicyclopentadiene dose led to an increase of this parameter for less than two fold. The addition of galvanic wastes to the SPCs resulted in a further increase in compressive strength for the corresponding SPC samples.

Effect of TBPF Microencapsulated Ammonium Polyphosphate on the Properties of Thermoplastic Polyurethane Elastomer

In our previous work, ammonium polyphosphate (APP) microcapsule with the shell of boron modified phenolic resin (BPF) was prepared, recorded as BPFAPP. However, the compatibility and the flame retardancy of BPFAPP in thermoplastic polyurethane elastomer (TPU) are still not very good due to the brittle and hard shell wall. To improve the brittleness of microcapsules shell and the property reinforcements of APP in TPU, APP was encapsulated with the tung oil and boron modified phenolic resin (TBPF) in this paper, recorded as TBPFAPP. The property reinforcements of TBPFAPP in TPU were studied. The thermogravimetry, limiting oxygen index and cone calorimetry analysis showed that TPU/TBPFAPP composite had higher char yield and better flame resistance. The tensile strength and elongation at break showed that the mechanical properties were also significantly improved due to the introduction of α-Eleostearate.

Mass Transfer Modeling of α‐Eleostearic Acid from Tung Oil Concentration by Low‐Temperature Crystallization

AbstractWith the significant attention paid to α‐eleostearic acid (α‐ESA) in a variety of biologically beneficial effects, the demand for high‐concentration products is increasing. A method of cryogenic separation to predict the mass variation of α‐ESA from tung oil was established in this study. The results showed that the best α‐ESA crystallization condition was −20 °C in ethanol, which implied a low energy consumption when compared with the common crystallization temperature of −60 °C. The α‐ESA concentration in the liquid phase was reduced by 90.4% compared to tung oil, and most of the α‐ESA in the solution was recovered by mass transfer. On the other hand, a mathematical model based on the diffusion reaction theory is used in mass variation prediction. The effects of temperature and time on the mass variation in α‐ESA in solution crystallization were examined. The results showed that the proposed model could estimate the composition and total mass of winterized tung oil at R2=0.974. The model was validated by experiments with an error of ±10%.