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Abstract Emulsion formation is one of the most important problems faced by petroleum companies to guarantee the flow of fluids during petroleum production, once its formation is often associated to the colloidal state of asphaltenes in petroleum. For this reason, chemical additives should be frequently used to stabilize the asphaltenes and reduce or prevent emulsion formation. Unfortunately, it does not exist any widespread chemical compound that could be used for petroleum reservoirs indistinctly. Consequently, scanning and screening analysis for new compounds should be performed with the purpose to find more efficient and eco-friendlier demulsifiers. In this paper, four different chemical routes (hydrogenation, ethoxylation, formaldehyde polycondensation, and ethoxylation of formaldehyde polycondensation) have been used to synthetize four new products from cardanol to evaluate their activity as demulsifier agents. These additives were characterized by FTIR and 1H NMR analysis. The demulsification activity were studied in emulsions using three Brazilian crude oil produced with a 30% (v/v) brine cut, 60 and 240 g/L NaCl of salinity, at different pH (range from 3 to 10), under agitation (3200 rpm). Bottle test was carried out at 60 °C in graduated tubes for water separability tests, by adding a constant composition (200 ppm) of each chemical tested. The results show that demulsification is more significant for ethoxylated compounds, at neutral pH. [ABSTRACT FROM AUTHOR]

A novel cardanol‐based siloxane (SAECD), which has silicon groups and reactive epoxy groups, was synthesized. Its structure was confirmed by Fourier transform infrared spectrometry and 1H nuclear magnetic resonance. Then, phenolic foams (PFs) modified with different contents of SAECD were prepared. While addition of appropriate amount of SAECD into resin matrix enhances the flexural strength of PFs, incorporation of SAECD into PFs leads to a reduced pulverization ratio. The limiting oxygen index (LOI) increases continuously with the increasing addition of SAECD into PFs. The results of the cone calorimeter test showed that the addition of 3% SAECD could effectively reduce the heat release rate and total heat release of the foam by the condensed phase flame retardant mechanism. The TTI of the modified foam was delayed by 19 s; the PHRR, mean HRR, and THR of the modified foams decreased by 9.10%, 4.11%, and 7.55%, respectively, compared with those of the pristine PF. In addition to the increase in the toughness of the PF, SAECD addition can also improve the flame retardant properties of the PF. [ABSTRACT FROM AUTHOR]

Owing to the natural abundance, variety of structural features, and highly specific functions, natural monomers render themselves as potential candidates for production of high performance functional polymers. The emerging concept of the biorefinery and development of new biosynthetic routes to synthesize a versatile and broad spectrum of natural monomers and polymers continues to gain momentum. The production of high quality polymers from renewable feedstocks requires innovative chemical modifications and catalytic transformations to achieve higher yields in an efficient manner. A fresh look into monomers available from natural resources such as terpenes, rosin, glycerol, furans, tannins, suberin, their derivatives and miscellaneous monomers may inspire future applications with impactful biobased materials. There are also many areas that require urgent discussion and review pertaining to recent developments in the field; this includes monomer sources that give molecules having special structural features. In particular, cardanol, a naturally occurring low-molecular-weight compound is unique as it contains a phenolic head group and a hydrocarbon chain with different degrees of unsaturation. This molecule possesses functional groups that are amenable for classical chemical modification, which is instrumental in developing a wide range of functional monomers and polymers. A large number of soft and hard materials have been developed from cardanol-based monomers. During the past, a large number of industrial grade materials have been developed from plant-based monomers, including development from microbial and fermentation processes (i.e. lactic acid). This review provides a comprehensive study and survey on recent developments on monomers and polymers derived from urushiol and cardanol based monomers and polymers, vegetable oil-based monomers and polymers, microbially produced monomers and polymers. These all represent emerging fronts giving a vast scope while highlighting important potential material and reagent opportunities. [ABSTRACT FROM AUTHOR]

• PLA and ABS were mixed by reactive extrusion with epoxidized cardanol compounds. • Epoxidized cardanol and its mixture with raw cardanol were tested. • Both approach led a substantial increase of the compatibility of PLA and ABS. • The mixture led a synergistic effect on the mechanical properties. • Impact strength increased of 172% and strain at break more than 1000% vs PLA. With the aim to reinforce polylactide (PLA) mechanical properties, poly(acrylonitrile-butadienestyrene) (ABS) is considered as a polymer of choice. However, PLA and ABS are immiscible, leading to blends with weak properties. Cardanol is a lipid phenolic known to compatibilize these two polymers thanks to its reaction with ABS, but does not react with PLA and restricts its use to the modification of ABS. In this work, we investigated the effect of cardanol-based compatibilizers able to react by reactive extrusion with both PLA and ABS. In a first approach, cardanol unsaturations were epoxidized (CardE), hoping to react with PLA, while cardanol phenolic group would react with ABS. This compatibilizer was efficient as attested by ABS nodules size reduction and dispersion within PLA, in addition to the merging of the relaxation temperatures of both polymers at 69.5 °C when 5 wt% CardE was used. In addition, it led to a substantial improvement of PLA/ABS impact strength and elongation at break. In a second approach, we used of a mixture of compatibilizers, containing raw and epoxidized cardanol, both of them reacting either with PLA or with ABS. Here, a clear synergistic effect was observed, as attested by the exceptional increases of both impact strength (+172% compared to neat PLA) and elongation at break (+1000% compared to neat PLA). We assumed modified chains of both PLA and ABS with cardanol derivatives during reactive extrusion would intersperse between PLA and ABS, reducing the interfacial tension and improving the interfacial adhesion, leading to the outstanding compatibilization of the blend. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Cardanol is used as a bio-resource. • Synthesis of novel P and Si based precursors. • Synthesized precursors are successfully incorporated in the PU backbone for the flame-retardant applications. • Limiting oxygen index (LOI) achieved is 29 for the coating formulation with the equal concentrations of precursors. • All the coatings retained good mechanical properties even with the incorporation of the precursors in the system. Abstract In the evolving resin world, people are trying to develop the resins from bio-resources with the properties similar to or superior to the commercial resins. This research work presents an attempt to develop the flame-retardant coating from cardanol as a starting material. The two intermediates obtained using Phenylphosphonic dichloride (PPDC) and Dichlorodimethylsilane (DCDMS) are used in the development of polyurethane backbone in various proportions. Itaconic acid (IA) based polyol was used as a chain extender for curing. Characterization of the intermediates obtained was done using the Fourier transform infrared (FTIR) spectroscopy, Nuclear magnetic resonance (NMR) spectroscopy, acid value, hydroxyl value, epoxy value, etc. All the characterizations showed that the required products have been formed. The Coated films showed similar mechanical properties which were analyzed using flexibility, impact resistance and pencil hardness. The gel content and water absorption values obtained are inversely proportional to each other which can be correlated with the barrier properties of the films. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) showed that the FR50 produced the maximum amount of char and FR100 had the highest T g with the value of 81.68 °C. Flame retardancy of the cured films was checked using the limiting oxygen index (LOI) and UL- 94 vertical burning test. All the coating films with the developed precursors were able to self-extinguish the fire within 10 s and FR50 obtained 29 as the highest value of LOI. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Synthesis of fully bio-based substituents of phthalate plasticizer for PVC films associating cardanol and fatty chains. • Thermal stability and plasticizing properties of PVC films coming from grafting and epoxidation of fatty chains on cardanol. • Low eco-toxicity and reprotoxicity of plasticizers for both, female and male hormones. Abstract A series of bio-based epoxidized plasticizers (CExEp) for soft PVC was synthesized from cardanol and various fatty acids by esterification and epoxidation of the fatty and cardanol unsaturations. The plasticizing properties of these additives for PVC films were proved considering thermal and mechanical data. They seem to be a potential bio-based alternative plasticizer to diisononyl phthalate (DINP), one of the most widespread phthalate plasticizers, with less rigid and stable films. The synergy between epoxy groups, cardanol ring and fatty chains to elaborate efficient primary plasticizers was demonstrated. Moreover, the eco-toxicity using daphnies, algae, and plants as model organisms and endocrinal disruptor tests (YES/YAS) were realized. Our results revealed that the fatty cardanol plasticizer causes a global decrease in toxicity compared to DINP and no harm for environment and human health were detected without endocrine perturbation effect. These positive results of toxicology allow to consider these cardanol plasticizers in industrial applications as alternative to DINP. [ABSTRACT FROM AUTHOR]

Highlights • Cardanol has been prepared from nutshell liquid and tested as a corrosion inhibitor. • The inhibition corrosion capacity of cardanol was studied for Al in biodiesel. • The inhibitive action is due to the adsorption of cardanol molecules on Al surface. • Maximum efficiency (93.2%) was observed at 200 ppm. • Chemical and electrochemical studies gave similar results. Abstract Here we investigate the inhibition capacity of cardanol for the corrosion of aluminum alloy 5052 H32 (AA 5052 H32) in biodiesel using electrochemical impedance spectroscopy and weight loss methods. The results showed that the inhibition efficiency increases with an increase in the concentration of cardanol. The inhibitive action of cardanol is due to the adsorption of cardanol molecules on the AA 5052 H32 surface without the variation in the corrosion mechanism. The widening of phase angle maxima at an intermediate frequency by adding cardanol confirms the adsorption of a film of cardanol molecules on the AA 5052 H32 surface. [ABSTRACT FROM AUTHOR]

Well‐defined linear alkyl benzene surfactants (COxn) were successfully synthesized using cardanol as a green phenolic alternative and initiator for polyoxazoline (POx), the hydrophilic block of nonionic surfactants. Various hydrophilic lipophilic balance values were investigated by varying the POx length according to the [monomer]/[initiator] ratio. The chemical structure of the surfactants, in particular the terminal groups, was well identified by matrix assisted laser desorption ionization time of flight mass spectrometry demonstrating the good progress of the cationic ring‐opening polymerization. The COxn surfactants spontaneously self‐assembled in water at a critical aggregation concentration of 1–2 µmol L−1 into nano‐objects characterized by a hydrodynamic diameter of 11–24 nm and a number of aggregations ranging from 30 to 60 according to the worm‐like micelle model. © 2019 Society of Chemical Industry An alternative to nonyl phenol ethoxylate surfactants is described using cardanol as a bio‐based phenolic building block and polyoxazoline as a polyethylene oxide alternative. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Synthesis of a series of copolymers containing plant-based cardanol and zwitterionic moieties. • Transparent thin-films prepared by spin-coating and UV-crosslinking processes. • High bactericidal property with larger content of cardanol moiety in the copolymer. • Excellent adhesion resistance to biofoulants with the increase of the zwitterionic moiety. • Sufficient biocompatibility regardless of the ratio of cardanol and zwitterionic moieties. Abstract A series of copolymers (PSH#s, where # is the molar content (%) of (dimethylamino)ethylmethacrylate (DMAEMA) and sulfobetaine methacrylate (SBMA)) containing both plant-based cardanol and zwitterionic moieties was synthesized via free radical polymerization of 2-hydroxy-3-cardanylpropyl methacrylate (HCPM) and DMAEMA, followed by betainisation with 1,3-propanesultone. Transparent PSH# films could be prepared on the silicon wafers through spin-coating and UV-crosslinking processes. The bactericidal and antifouling properties of the polymer films were found to be closely related to the ratio of the HCPM and SBMA moieties in the copolymers. The films having a larger content of the bactericidal HCPM moiety show better bactericidal properties, while those having a larger content of the hydrophilic SBMA moiety show enhanced adhesion resistance to biofoulants. Moreover, all the films having both HCPM and SBMA moieties have sufficient biocompatibility, regardless of their ratio. [ABSTRACT FROM AUTHOR]

A UV-curable cardanol-based monomer (ECGE) was prepared using cardanol and epichlorohydrin, followed by epoxidation of the unsaturation in alkyl side chains of cardanol segments. After its chemical structure was confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance (1H NMR), ECGE was used as a reactive diluent to copolymerize with castor oil-based polyurethane acrylate (PUA) and a series of UV-curable coatings were prepared. Results showed that the viscosity and volume shrinkage of the UV-curable PUA system decreased significantly after the introduction of cardanol-based monomer while maintaining reasonably high bio-renewable contents; when containing 50% of ECGE, the biomass content reaches 66.2%, which is 1.41 times that of pure resin. In addition, the coating properties were evaluated to determine hardness, adhesion, flexibility, and water resistance. The properties of UV-curable thermoset were also studied using tensile testing, dynamic mechanical thermal analysis, and thermogravimetric analysis. The cardanol-based coatings showed excellent adhesion, flexibility, medium hardness, and enhanced char yield although tensile strength, tensile modulus and glass transition temperatures were somewhat diminished. All these performances can be attributed to the unique architectures of ECGE that combined the structural features of rigid benzene ring and long flexible alkyl chains. The UV-curing behavior was determined using real-time IR, and the results indicated that the conversion of unsaturated bond was increased with more concentration of ECGE. [ABSTRACT FROM AUTHOR]

Aedes aegypti and Culex quinquefasciatus are vectors of diseases that constitute public health problems. The discovery of products capable of inhibiting their development which are less harmful to the environment would have a huge impact on vector control. Here, natural cashew nut shell liquid (CNSL), technical CNSL, anacardic acid, cardanol, and cardol were isolated from Anacardium occidentale and evaluated for larvicidal and pupicidal activity against Ae. aegypti and Cx. quinquefasciatus under laboratory and field conditions. The activities of phenol, resorcinol, salicylic acid, and pentadecane, commercial chemicals similar in structure to nut shell derivatives, were also evaluated. All of the fractions extracted from A. occidentale oil exerted larvicidal effects against both mosquito species (LC50 5.4-22.6 mg/L), and two of the aforementioned were effective against pupae (LC50 90.8-109.7 mg/L). Of all the fractions tested, cardol demonstrated the strongest larvicidal and pupicidal effects and presented the most prolonged residual activity against the larvae and pupae of Ae. aegypti and Cx. quinquefasciatus under field conditions. This study suggests that A. occidentale nut shell derivatives are sustainable and promising candidates for the development of novel insecticides to overcome the problem of harmful chemical insecticides. [ABSTRACT FROM AUTHOR]

Abstract Cardanol was obtained by vacuum distillation of "cashew nut shell liquid" (CNSL). Cardanol is a by-product of cashew production and a building block for chemical synthesis; cardanol and its derivatives can be used for different types of applications. Three of these compounds are the subject of the present NMR study and theoretical comparison. 1H and 13C NMR signals were assigned using 1D and 2D NMR experiments. The DFT/B3LYP method using the cc-pVTZ basis set was employed for the calculations of the 1H and 13C NMR chemical shifts (δ). The obtained data were used as an auxiliary tool for unequivocal assignment of all 1H and 1³C NMR signals. For these compounds, the adopted theoretical model was sufficient to obtain a good description of the chemical shifts. Graphical abstract Cardanol is a by-product of cashew production and a building block for chemical synthesis; cardanol and its derivatives can be used for different types of applications. Three of these compounds are the subject of the present NMR study and theoretical comparison. Image Highlights • Chemical shift calculations using the DFT/B3LYP method. • Complete NMR assignment for three cardanol derivatives. • Experimental and theoretical approach. [ABSTRACT FROM AUTHOR]

Highlights • Hydrolysis of t-CNSL and cardanol epoxides is reported for the first time. • Methanolysis of t-CNSL and cardanol epoxides is also unpublished. • Oxygenated cardanol derivatives gave remarkable oxidative stability to biodiesel. • A new polyol derived from cardanol proved to be an excellent antioxidant additive. • Oxygenated derivatives had better thermal stability than t-CNSL and cardanol. Abstract Biodiesel demand is increasing all over the world. The maintenance of oxidative stability is extremely important to biodiesel market, from the point of view of the quality of the fuel as the economic amount involved. In the present work, we synthesized new antioxidant candidates for biodiesel from chemical transformations in alkyl phenols present in technical cashew nut shell liquid (t-CNSL) and, more specifically, in cardanols isolated from t-CNSL. This raw material is viable, easy accessed and low cost. Five chemical transformations were performed in both t-CNSL and cardanols with yields from 50% to 92%. The starting materials and their respective derivatives were characterized by 1H NMR, 13C NMR and IR. Antioxidant activity and thermal stability of the products were evaluated. The induction period for pure biodiesel was 6.35 h and the addition of 0.5% (w/w) of cardanols increased to 7.37 h. Two products presented excellent antioxidant activity, epoxidized cardanols (4) and hydrolyzed cardanols (6). They increased the induction period to 15.05 h and 18.62 h, respectively. The oxygenated derivatives also showed better thermal stability than the starting materials. [ABSTRACT FROM AUTHOR]

Series of cardanol polyoxyethylene ether carboxylates were synthesized with biomass cardanol as material to study their physicochemical properties at the interface. The surface tensions of the cardanol nonionic-anionic surfactants were measured at 25 °C and the thermodynamic parameters of adsorption were also calculated. The surface activity and thermodynamic properties of the cardanol nonionic-anionic surfactants were correlated to their chemical structures. With increasing of the number of the ethoxylation unit in the hydrophilic group, a decrease in adsorption efficiency and an increase in surface tension at critical micelle concentration and thermodynamic free energy of adsoption were observed and were attributed to a decrease in adsorption of the cardanol nonionic-anionic surfactants at the interface. Series of the cardanol nonionic-anionic surfactants have good wettability and foaming property. The foaming capacity and the foaming stability of the solution of the cardanol nonionic-anionic surfactants increase by decreasing in the ethoxylation unit and by increasing the double bond of the hydrophobic group. The physicochemical properties of the cardanol nonionic-anionic surfactants at the interface are correlated to the chemical structures of the investigated surfactants, and there is the synergy effect between the nonionic hydrophilic group and the anionic hydrophilic group at the interface. [ABSTRACT FROM AUTHOR]

Abstract The toxic petroleum-based phthalates account 80% of the total plasticizer consumption in China. Conventional methods for preparing epoxy plasticizers produces a large amount of waste water. Furthermore, cardanol (a byproduct of cashew nut processing) has the potential to be an economic alternative for producing fine chemical products. Here we reported a strategy for acid-free catalytic production of epoxy plasticizer using renewable waste material cardanol as starting material and quaternary ammonium phosphotungstate as catalyst. The optimum epoxidation reaction parameters were investigated and the epoxy value of epoxidized cardanol based plasticizer was 5.2% at optimal reaction conditions. Remarkably, the catalyst was recycled and the percent recovery in the first recycle was 89.0%. Performances of plasticized PVC films showed that epoxidized cardanol based plasticizer improved thermal stability and decreased the glass transition temperature of PVC. Plasticizing efficiency of epoxidized cardanol based plasticizer reached 82.2%. Epoxidized cardanol based plasticizer is biologically safe without acute toxicity and showed more excellent solvent resistance and lower volatilization than dioctyl phthalate. In conclusion, a cleaner environment-friendly plasticizer derived from a waste material was produced by acid-free catalysis. The strategy introduced renewable waste material cardanol into the environment-friendly plasticizer production to substitute dioctyl phthalate and had potential application value to reduce pollution and improve human health. Graphical abstract Image 1 Highlights • An improved cleaner epoxy plasticizer from a byproduct of cashew nut processing. • Production of cleaner epoxy plasticizer via a acid-free catalysis method. • Quaternary ammonium phosphotungstate was prepared and used as catalyst. • Solvent resistance of obtained epoxy plasticizer is better than toxic DOP. [ABSTRACT FROM AUTHOR]

Abstract In the present work, we developed a green and more efficient method to prepare biobased polyurethane (PU) foams under catalyst-free condition. Firstly, novel organosilicon grafting cardanol-based autocatalytic polyols (SCAPs) with low viscosity were synthesized through the ring opening of cardanol glycidyl ether (CGE) and the hydrosilation of unsaturated alkyl chain with heptamethyltrisiloxane (HMTS). Subsequently, PU foams were synthesized by SCAPs in absence of catalyst. The structure and properties of the PU foams were evaluated and discussed. In addition, the thermal degradation mechanism of PU foams was investigated by using a thermogravimetric analysis instrument coupled with fourier transform infrared and mass spectrometer (TG-FTIR-MS). The results showed that the PU foams had high compression strength and thermo-stability. Graphical abstract Image 1 Highlights • Two novel bio-based autocatalytic polyols (SCAPs) with low viscosity were successfully synthesized from cardanol. • Bio-based PU foams were further prepared from SCAPs in the absence of catalyst. • The thermal degradation mechanism of obtained bio-based PU foams was systematically investigated by TG-FTIR-MS. • The bio-based PU foams showed uniform closed-cell structure, and had high compression strength and thermostability. [ABSTRACT FROM AUTHOR]

Multiarm cardanol-based oligomers with a cyclotriphosphazene core were prepared through a nucleophilic substitution reaction; the structures of oligomers were fully characterized and confirmed through Fourier transfer infrared spectrometry, 1H nuclear magnetic resonance (NMR), 31P NMR, and gel permeation chromatography. The designed multiarm bio-based acrylates (AECC) were successfully prepared by epoxidizing the unsaturated aliphatic chain of cardanol segments with m-chloroperoxybenzoic acid and acrylating epoxy groups. The synthesized oligomers contain rigid phosphazene/benzene rings as "hard cores" and long aliphatic chains as "flexible shells." Compared with commercial hyperbranched polyurethane acrylate (CN2302) and acrylated epoxidized soybean oil, cured AECC coatings and films exhibited not only greater hardness, excellent adhesion, higher glass transition temperatures, and excellent mechanical properties but also good thermal stability and biodegradability. We successfully obtained a high-performance UV-curing resin that has a high biorenewable material content and can meet basic daily requirements. [ABSTRACT FROM AUTHOR]

In the present paper, a novel epichlorohydrin/cardanol adhesive was reinforced by multi-walled carbon nanotubes (MWCNTs) and characterized experimentally. The adhesive was reinforced by MWCNTs in weight ratios (wt %) of 0.5%, 1.0% and 2.0%. The bulk properties of the reinforced adhesive were characterized through dynamic mechanical analysis tests, tension tests, and fracture toughness tests, while its shear behavior was characterized through single-lap shear tests on aluminum and composite bonded specimens. The morphology of the reinforced adhesive was characterized using scanning electron microscopy tests. Due to the high viscosity of the bio-based adhesive, special efforts were placed on the dispersion of the MWCNTs into the adhesive, which was achieved through mechanical mixing. The results from the tests show that the presence of the MWCNTs increases the glass transition temperature, the Young’s modulus and the fracture toughness of the reinforced bio-based adhesive, while it decreases its tensile strength. This contradictory finding is attributed to the formation of MWCNT agglomerates into the adhesive. For the content of 2.0 wt %, the shear strength of the reinforced adhesive is increased by 57% for the aluminum joints and by 10.4% for the composite joints. The findings of the study reveal that the reinforcement of the bio-based adhesive by MWCNTs is feasible from a manufacturing viewpoint and may increase the efficiency of the adhesive in structural applications.

• A double dynamically crosslinked cardanol derived epoxy vitrimer was fabricated. • The obtained vitrimers demonstrated advantages of multi-stimulus responsiveness. • Mechanical and chemical recovery, and biodegradability were revealed by the vitrimer. • The EDCS/DPTA/G composites exhibited excellent degradability in alkaline solution. Dynamic covalent chemistry provides a solution to the recycling problem of epoxy resins, and the graphene functional composites. Nevertheless, the study on chemical structures of the curing agent, and the type of dynamic covalent bonds associated with the nature of the epoxy resins still face challenge due to unclear mechanism and improper design strategy. Herein, a bio-based epoxy monomer was designed from cardanol, and used to fabricate a double dynamically crosslinked epoxy vitrimer. The mechanical properties, dynamic mechanical properties, thermal stability, relaxation behavior, self-healing efficiency, recovery, and reprocessing efficiency of the resulting resins were investigated, focusing on the effects of the soft and hard structure of the curing agent, and the types of dynamic covalent bonds. Bio-based epoxy vitrimers demonstrated several advantages, including multi-stimulus responsiveness, multi-channel self-healing ability, mechanical and chemical recovery, and biodegradability. Specifically, the epoxy vitrimers containing rigid furan rings exhibited better mechanical properties (6.85 MPa) and stability (T g = 40.81 °C) compared to those with flexible fatty chains. Additionally, the double dynamically crosslinked vitrimer showed faster stress relaxation time (5.6 min) and lower activation energy (36.58 kJ/mol) compared to systems with a single dynamic bond. Finally, the addition of graphene enabled the production of cardanol-based composites with conductivity. Overall, the ease with bio-based epoxy vitrimer and its composites with excellent degradability can be fabricated, utilized, recycled and re-used, which is a novel direction for sustainable composites. [ABSTRACT FROM AUTHOR]

Defects in the curing process of epoxy coatings tend to deteriorate the anticorrosion performance of the coatings. An important way to enhance the anticorrosion performance of epoxy coatings is to add flaky fillers. In this paper, anisotropic Janus nanosheets (JNs) were prepared and modified by cardanol (CA) and Zn2+. Then, the obtained CA@JNs@Zn2+ Janus composite nanosheets were introduced into epoxy coatings. When the content of CA@JNs@Zn2+ is 0.2 %, the mechanical properties and corrosion resistance of the coating were effectively improved. The tensile strength of 0.2 %-CA@JNs@Zn2+/EP coating is 79 % higher than that of pure epoxy coating. The EIS analysis showed that the low-frequency impedance of the coating remained as high as 16.45 Gohm·cm2 after 35 days of immersion, and remained above 10 Gohm·cm2 during the whole immersion period, which demonstrating the optimal corrosion resistance. This paper provides a theoretical basis for the preliminary application of Janus material in the field of anticorrosion, and the prepared composite coatings are expected to be used for anticorrosion in harsh environment. [Display omitted] • Janus nanosheets with amino and thiol groups on the opposite sides was prepared. • Cardanol grafted onto thiol by click increases the dispersion of JNs in EP coating. • Zn2+ coordinated with amino groups improves the corrosion performance of coating. • Janus gets good dispersion and anti-corrosion organic-inorganic composite coating. [ABSTRACT FROM AUTHOR]

In this work, an eco-friendly approach to the extraction of cashew nut shell liquid (CNSL) and the refinement of cardanol were explored for the first time using cashew nut produced in Hainan, China as raw material. Cashew nut shell (CNS) are usually disposed of as waste from agricultural processing, but CNSL extracted from CNS by solvent extraction or supercritical CO 2 extraction has a high value. The composition of CNSL extracted by different conditions varies, and more CNSL is extracted by relatively less polar solvent. Supercritical CO 2 extraction, as an environmentally friendly method, also showed good superiority in the extraction of CNSL. CNSL produced from Hainan cashew nuts contains high level of anacardic acid. The extracted CNSL can be decarboxylated and separated to obtain a mixture of cardanol consisting of four olefins containing different numbers of double bonds. Cardanol can be converted to saturated cardanol by catalytic hydrogenation and catalytic transfer hydrogenation, and the catalytic transfer hydrogenation also exhibits selectivity by selecting a suitable hydrogen donor to obtain high purity cardanol, monoene. Both saturated cardanol and cardanol, monoene have good prospects for utilization due to their chemical structure. [Display omitted] • Hainan cashew was used for extraction for the first time. • A method for obtaining saturated cardanol and cardanol, monoene was proposed. • The effect of supercritical CO 2 above 30 MPa on the extraction was investigated. • Calcium hydroxide reduce the temperature required for the decarboxylation. • Cardanol, monoene was synthesized by catalytic transfer hydrogenation. [ABSTRACT FROM AUTHOR]

Thermoplastic cassava starch films were synthesized using native cassava starch plasticized with glycerol and cardanol-based plasticizers at 70:30, 80:20, and 90:10 ratios. Cardanol-based plasticizers were cardanol, epoxidized cardanol, and cardanol polyol. The effectiveness of the synthesis of epoxidized cardanol and cardanol polyol was assessed by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (NMR) spectroscopy. The starch bioplastics were extruded in 3 mm filaments and characterized by tensile testing, water absorption, humidity and thermogravimetric analysis. Results showed a strong effect of the concentration of cardanol-based co-plasticizers on the mechanical properties with 20-fold increase in modulus, 4-fold increase in tensile strength, and half decrease in elongation. The moisture content was also significantly decreased in increasing co-plasticizer content. SEM micrographs showed a good compatibility, but also some voids. No significant difference, however, was observed for the water absorption properties. Thermal resistance was also improved for cardanol and epoxidized cardanol films. • Successful ring opening of epoxidized cardanol to obtain novel cardanol polyol. • Significant improvement of mechanical, thermal and moisture-resistance properties. • Improvement of properties with higher concentration of cardanol-based plasticizers. • Developed plasticizers are green co-plasticizers for starch-based materials. [ABSTRACT FROM AUTHOR]

“Green” resole phenolic resins for laminating applications were synthesized, and their properties and thermal stability were determined. The plant-based cardanol and condensed tannin were used as the partial substitutes of up to 40% of the phenol in the synthesis of the phenolic resins. The resins were synthesized with different proportions of phenol (P) to cardanol (C) and with different total molar ratio to the formaldehyde (F) in the resins (1.25 to 2.0). An increased cardanol content resulted in a proportional increase in the flexibility and fracture toughness of the cured cardanol-phenol-formaldehyde (CPF) resins. Also, a direct proportionality was found between increasing cardanol content and decreased crosslink density of the CPF resins. The best results were obtained with the formulation with a P:F molar ratio equal to 1:1.25. Tannin was incorporated into the CPF resins and the fracture toughness and flexibility values of the cured Tannin-CPF resins were found to be proportional to and increasing with the tannin content. However, glass transition temperature (Tg), flexural stress, and flexural modulus values of the CPF resins decreased with the tannin content. TGA-FTIR study of the resins was carried out and the emitted gas species during the pyrolysis of the samples were identified. The thermal stability and the temperature of degradation of the cured CPF resins decreased with increasing cardanol content.

Cardanol-based epoxidized resole resins (ERCF) were synthesized by reacting resole type phenolic resin (RCF) and epichlorohydrin in basic medium, at 120 °C. Resole type phenolic resins were synthesized by reacting cardanol (C) and formaldehyde (F) in the presence of sodium hydroxide, as catalyst, at five different temperatures ranging between 60-80 °C with an interval of 5 °C for a maximum period of 6h. These prepared samples were cured using 15% polyamide as curing agent at 120 ± 2 °C for 1h. Mechanical and chemical resistance characteristics of prepared samples were evaluated to assess the possibility of using such thermosetting resins as a new eco-friendly material for engineering applications. Upon evaluation, it was found that the prepared resins systems exhibit better properties compared to commercial epoxy resin in term of increase in tensile strength, elongation-at-break and impact strength, of castings and gloss, scratch hardness, adhesion and flexibility of the films. The anticorrosive properties from chemical resistance of the prepared resin systems are found to be superior than unmodified epoxy resins. The TG/DTG thermograms showed two step decomposition behaviors in all the prepared samples.

Cashew nut shell liquid (CNSL) is an economically important by-product obtained from the cashew nut Anacardium occidentale L. The liquid has been found to be versatile with a wide range of uses, including as a raw material in the polymer industry, in the development of drugs (antioxidants) and in pest control. One important chemical component of CNSL known for its bioactivity is cardanol. We isolated (8 Z ,11 Z)-3-(8,11,14-pentadecatrienyl)phenol, a cardanol from CNSL, and determined its insecticidal and progeny growth and development inhibition activities against Tribolium castaneum Hebst. We used a bioassay-guided approach for the isolation. Exposure to cardanol produced 80% mortality of adult T. castaneum in the insecticidal bioassay. In the progeny growth and development inhibition bioassay, 46.7% of larvae were killed, and only 20.7% of adults emerged without deformities after the cardanol treatment. The amount of isolated cardanol from the 1 g equivalent/ml extracted CNSL was found to be 36.55 mg with LC50 value of 47.88 mg/ml and 13.28 mg/ml against adult T. castaneum and its larvae, respectively. We conclude that cardanol can potentially be useful in managing stored product insect pests, especially T. castaneum , but with the prerequisite that one should take much care when handling and when applying the compound. [ABSTRACT FROM AUTHOR]

Abstract Starting from renewable Cardanol, a novel inherently fire-retardant UV curable bio-based prepolymer (AEHCPP) with phosphazene core and six Cardanol arms are prepared in this report. The chemical structure of all newly prepared intermediates compounds and AEHCPP are well-characterized using nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR). UV-curable mixture consisting of AEHCPP and different diluents were formulated and their photopolymerization dynamics were investigated on Photo-calorimetry (photo-DSC). The thermal properties of crosslinked coatings were estimated using thermal analysis technology. Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) results show that glass transition temperatures of all cured films are above room temperature (>30 °C), the 5% weight loss temperature in nitrogen is higher than 266 °C. The fire-retardant properties are estimated by TGA and all calculated Limiting Oxygen Index (LOI) values are over 24, implying the excellent fire-resistance of cured films. Highlights • Cardanol-based, star-shaped bio-prepolymer. • UV-curable prepolymer with phosphazene core. • Green and inherent fire-retardancy. • Excellent thermal stability of UV-cured films. [ABSTRACT FROM AUTHOR]

Abstract: Cardanol, the meta-substituted phenol, is subjected to diazotization with p-chloroaniline to get diazotized p-chloroaniline cardanol dye. We report a series of interpenetrating polymer networks (IPNs) synthesized by condensing polyurethane of castor oil with diazotized p-chloroaniline cardanol-furfural as homopolymer using ethylene glycol dimethacrylate as cross-linker and benzoyl peroxide as an initiator. Synthesized IPNs were characterized by Fourier transform infrared spectroscopy. The thermal behaviour of IPNs was studied by thermogravimetric analysis and differential thermal analysis, and the kinetic parameters such as activation energy (Ea) and regression coefficient (R2) of reaction were calculated by using the Coats-Redfern method. The morphology was studied by XRD studies.Graphical abstract: [ABSTRACT FROM AUTHOR]

A series of phenolic bio‐oil components were selectively hydrodearomatized by palladium on carbon into the corresponding ketones or alcohols in excellent yields using polymethylhydrosiloxane and water as reducing agent. The selectivity of the reaction was governed by the water concentration where selectivity to alcohol was favoured at higher water concentrations. As phenolic bio‐oil examples cardanol and beech wood tar creosote were studied as substrate to the developed reaction conditions. Cardanol was hydrodearomatized into 3‐pentadecylcyclohexanone in excellent yield. From beech wood tar creosote, a mixture of cyclohexanols was produced. No hydrodeoxygenation occurred, suggesting the applicability of the reported method for the production of ketone‐alcohol oil from biomass. [ABSTRACT FROM AUTHOR]

This work is aimed to study the suitability of cardanol and its derivatives as plasticizers for poly(lactic acid), PLA. Differential scanning calorimetry (DSC) was used to assess the plasticizing effectiveness of cardanol (CARD) and its derivatives, cardanol acetate and epoxidated cardanol acetate, comparing the results with those obtained with a commercially available plasticizer, poly (ethylene glycol), PEG, with an average molecular weight of 400 g mol−1. Measurement of the glass transition temperature highlighted that, among the tested cardanol derivatives, neat cardanol is the most effective plasticizer for PLA. In fact, the glass transition temperature of PLA plasticized by CARD is only slightly higher than that of PLA plasticized by PEG. This is attributed to the lower compatibility between PLA and CARD compared to PLA and PEG, as estimated by the interaction radius. Therefore, cardanol could represent a technically valid, economic, and largely available plasticizer for PLA. Moreover, DSC, an X-ray diffraction analysis, showed that, compared to PEG, the addition of CARD involves a limited increase of the rate of crystallization, even in this case, due to its lower compatibility with PLA. Dynamic mechanical analysis showed that, below glass transition, PEG is able to reduce the stiffness of PLA by a higher extent. However, as the temperature increases, retention of the shear modulus of PEG-plasticized PLA is much higher than that of CARD-plasticized PLA. As a consequence, above glass transition, the stiffness of CARD-plasticized PLA becomes lower than that of PEG-plasticized PLA. Therefore, despite its lower compatibility with PLA, CARD can impart to plasticized PLA lower modulus compared to PEG, when the plasticizer content is high enough to reduce the glass transition below room temperature. [ABSTRACT FROM AUTHOR]

Novel bio-based acrylate was designed through the epoxy ring-opening reaction of cardanol glycidyl ether (CGE) with fatty acids from camelina oil (FACO), followed by epoxidation of unsaturated chains and then acrylation of the epoxides. Cardanol- and camelina oil-based acrylates were also respectively synthesized for comparison purposes. The bio-based acrylate coatings were then produced under UV-radiation from the acrylates monomers with an addition of a photoinitiator. Polymerization of the acrylates and synthesis of the monomers were observed using Fourier transform infrared (FTIR) spectroscopy, and the chemical structures and acryl contents of the acrylates were confirmed by proton nuclear magnetic resonance ( 1 H NMR). The mechanical and thermal properties of the cured acrylates were evaluated using tensile test, dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA). Observation of resistances to water, solvent, and hydrolytic degradation were conducted to water and toluene uptake test, methyl ethyl ketone (MEK) rub test, and a degradation test under sodium hydroxide solution. Gel content was measured to evaluate performance of the coatings, and other coating performances including gloss, adhesion, and pencil hardness were determined using the wood panel coated with the cured acrylates. Compared to acrylated epoxidized soybean oil (AESO) coating, the acrylate derived from the cardanol modified fatty acids showed higher tensile strength, hardness, glass transition temperature, thermal decomposition temperature at maximum degradation rate, and resistances to solvent and hydrolytic condition of the cured coating. Therefore, the newly designed acrylate is a great alternative to AESO. [ABSTRACT FROM AUTHOR]

Biodiesel is playing an important role in transport sector as a substitute for petroleum fuels. The present study diagnoses the use of phenolic biofuel blends namely, cardanol at higher fuel injection pressure on the performance and exhaust emissions of a direct injection, 4-stroke, single cylinder compression ignition engine. In this study, biofuel blends used with three different percentage composition of cardanol such as B10M10, B20M10 and B30M10. The results are compared with base line diesel operation at 180 bar standard injection pressure. The experimental results show better engine performance and exhaust emission characteristics for the biofuel blends at 220 bar injection pressure. Biofuel blend B20M10 gives better performance and emission results when compared to B30M10, and there is not much difference in the results when compared to B10M10. B20M10 blend gives slightly lower brake thermal efficiency (BTE), sharp reduction in carbon monoxide (CO), unburnt hydrocarbon (HC) and smoke emissions and drastic increase in oxides of nitrogen emissions (NOx), when compared to baseline diesel operation. [ABSTRACT FROM AUTHOR]

The recognition of the alarming increased cost and looming exhaustion of petroleum resources for the production of polymeric resins for versatile applications has prompted us to switch towards green and sustainable resources. There is an immediate urge to develop bio-based polymeric resins via sustainable routes with enhanced properties for their utilization in polymer and coating applications. The present investigation reports the synthesis and characterization of aliphatic amine, Hexamethylene tetramine (HMTA) modified Cardanol(Col)-Formaldehyde(F) (Col-FA) free standing films and coatings for versatile applications through the use of cost-effective and renewable starting material, Col (agro byproduct of cashew nut processing) and HMTA (optimum amount, 15%) obviating the toxic solvent usage. The result indicated transparent (red-yellow colored), homogenous Col-FA films with amorphous morphology, and can serve as an eco-friendly, thermally stable (up to 430–440 °C), chemically resistant (against various solvents), mechanically robust and biologically active (moderate activity) material. The overall synthesis strategy is environmentally benign, employs safer chemistry and is consistent with the principles of “Green Chemistry” (principles 1, 2, 3, 4, 5, 6, 7, 8, and 12). This is a highly desirable and excellent approach to develop free standing, transparent, flexible, thermally stable, chemically resistant and antibacterial thin films/coatings to increase the application of Col. [ABSTRACT FROM AUTHOR]

Abstract: The present work is attempting to synthesize and characterizations of a novel carbazole core containing cardanol based benzoxazine monomer from carbazole core containing aromatic diamine, cardanol and paraformaldehyde. In addition, carbazole core containing cardanol based benzoxazine polymer and various weight percentages of amine functionalized rice husk ash incorporated carbazole core containing cardanol based polybenzoxazine composites were prepared. The prepared polymer and its composites were characterized by FTIR, XRD, DSC, TGA and dielectric studies. The various studies confirm that the composites show increased Tg, higher char yield and better thermal stability compared to carbazole core containing cardanol based benzoxazine polymer. In addition to that the composites show significant decrease in the dielectric constant values than the neat cardanol based polybenzoxazine. The surface morphology and the distribution of rice husk ash in carbazole core containing cardanol based polybenzoxazine composites are confirmed by SEM and TEM analysis. Hence, the present study has attempted to prepared eco-friendly value added carbazole core containing cardanol based polybenzoxazine products for low dielectric constant applications by making use of biowaste for both matrix and reinforcement preparation to form biowaste based composites.Graphical Abstract: Schematic representation for the preparation of carbazole core containing cardanol based benzoxazine monomer, polybenzoxazine and biobased polybenzoxazine composites [ABSTRACT FROM AUTHOR]

Four amphiphilic cardanol-based phenol-amine resin block polyethers (CPAE) with different contents of ethylene oxide and propylene oxide were prepared and were characterized by FTIR and 1H NMR. The surface tension and the interfacial tension of four CPAE block polyethers were measured, and series of surface active parameters were also calculated. The surface activity and the interfacial activity of the CPAE block polyethers were correlated with their chemical structure. The cmc, γcmc, Гmax, and values decreased with an increase of the branching number and the molecular weight, but the Amin value increased. The equilibrium interfacial tension decreased with the increase of the concentration and the molecular weight of the CPAE block polyethers. The results of de-emulsification revealed that the CPAE block polyethers showed interesting de-emulsification efficiency towards the simulated emulsions used in our work. The structure of the CPAE block polyethers could influence the de-emulsification performance, especially the molecular block. The de-emulsification mechanism of the CPAE block polyethers was studied using a single-droplet protocol and the dynamic data of drainage time, half-life time, and rupture rate constant obtained were consistent with the de-emulsification efficiency of the CPAE block polyethers. [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to synthesize, to characterize and to evaluate the effects on tubular occlusion of new monomer derived from cashew nut shell liquid (CNSL), also studying the effects of acid challenge (AC) on dentin surfaces treated with desensitizers. Methods The intermediary cardanol-epoxy (CNE) was synthesized through epoxidation of CNSL, followed by synthesis of cardanol-methacrylate-epoxy (CNME) through methacryloyl chloride esterification. Products were purified through chromatography column and characterized by Fourier transform infrared spectrometry and nuclear magnetic resonance. Resinous dentin desensitizers were formulated containing either unsaturated cardanol (CNU), CNE or CNME. Dentin disks were divided into seven groups: SL — Smear-layer, EDTA — EDTA-treated only, GLUMA — Gluma Desensitizer, OCB — One Coat Bond, CNU — CNU desensitizer, CNE — CNE desensitizer and CNME — CNME desensitizer. Dentinal fluid rate (DFF) was obtained using a Flodec equipment and tubular occlusion employing a scanning electron microscope (SEM), before and after AC. Data of DFF were submitted to two-way ANOVA and Tukey’s test (p < 0.05). Results GLUMA showed the lower reduction in DFF when compared to the other products, which were statistically similar. Even after AC, CNME presented the most homogenous and occluded surface, while CNE and CNU were partially removed, GLUMA was completely removed and OCB keep an occluded, but irregular surface. Significance CNME showed a great reduction of DFF and a homogenous occluded surface, suggesting that it may be a suitable and acid-resistant treatment option for dentine hypersensitivity. [ABSTRACT FROM AUTHOR]

In the present study, phosphorus-sulphur containing di and tetra functional carboxyl curing agents were synthesized from renewable resource, cardanol and used in the preparation of high performance epoxy coatings. Structure of the curing agents was analysed by evaluating its acid and iodine number as well as spectroscopic and chromatographic techniques. Coatings were formulated by varying the ratio of epoxy adduct to curing agents on equivalent basis such as 1:0.6, 1:0.8 and 1:1. Further, the prepared coatings were characterized for mechanical, chemical, optical, thermal, anticorrosive and flame retardant properties. It was concluded that, with increase in concentration of flame retardant curing agents, anticorrosive as well as flame retardant properties of the coatings improved. This enhancement in the properties could be related to the synergistic effect of phosphorus and sulphur as well as chemical structure of curing agents. [ABSTRACT FROM AUTHOR]

A biobased diluent, cardanyl acrylate (CA), was synthesized from cardanol and used to modify a castor oil-based polyfunctional polyurethane acrylate (PUA) resin. Firstly, chemical structure of CA was characterized by FT-IR, 1 H NMR, and 13 C NMR. Subsequently, the effect of CA’s content on the biobased content, viscosity, and volumetric shrinkage of the obtained bioresins were studied and compared with the petroleum-based hydroxyethyl acrylate (HEA) diluent. Moreover, ultimate properties of the UV-cured biomaterials such as thermal, mechanical, coating, swelling, and hydrophobic properties were investigated. Finally, UV-curing kinetics of the resulting bioresins were determined by real-time IR. By the addition of CA, the biobased content of the resulting bioresins were improved and the viscosity and volumetric shrinkage were reduced. For example, the obtained bioresin containing 30% of CA possessed a biobased content of 62.8% and volumetric shrinkage of 9.51%, which were clearly better than those of the bioresin with 30% of HEA (50.8% and 21.94%), respectively. Furthermore, many other properties of the UV-cured biomaterials, such as thermal stability, coating’s hardness and adhesion, and hydrophobic properties, were improved by the incorporation of CA. The final C C conversions of the resulting bioresins were also enhanced by the addition of CA. Hence, the cardanol-based diluent showed good potential in the development of UV-curable coatings. [ABSTRACT FROM AUTHOR]

Commercial novolac‐type phenolic thermosets are mainly synthesized from highly toxic precursors such as phenol and formaldehyde. Herein, the phenolic chemistry is renewed with bio‐based and non‐toxic precursors such as cardanol and nonanal to elaborate flexible phenolic thermosets. The two‐step novolac strategy involves the synthesis of a cardanol nonanal pre‐polymer (PCN) prior to its cross‐linking in presence of a supplementary amount of nonanal hardener. The curing process is optimized by rheology measurement and thermogravimetry analysis. The alkyl chains of this phenolic network induces soft mechanical properties acting as internal plasticizers. The softening of the resulting networks do not induce a loss of thermal stability. Showing a good compromise between softness and high thermal resistance, cardanol‐nonanal networks (RCN) seem to be relevant examples of an innovative and biobased approach for phenolic chemistry to design bio‐sourced materials without any petro‐based or hazardous molecules. Practical Applications: Various practical applications where smooth and soft coatings are employed can be considered. Novolac chemistry for bio‐based and notoxic resources: cardanol and nonanal. Softness and high thermal resistance phenolic resins are elaborated. These materials are based on internal plasticized cross‐linked materials. [ABSTRACT FROM AUTHOR]

A novel kind of biobased monomer, epoxidized cardanol‐based acrylate (ECA), was successfully synthesized from cardanol via acrylation and epoxidization. The chemical structure was confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance. Then, the ECA was employed to produce UV‐curable films and coatings copolymerized with castor oil‐based polyurethane acrylate. Compared to coatings from petroleum‐based diluent hydroxyethyl acrylate‐based castor oil‐based polyurethane acrylate resins, ECA‐based biomaterials exhibited a little inferior dilution ability but overcome the drawback of high volumetric shrinkage with a special lower value. Moreover, ultimate properties of the UV‐cured biomaterials such as thermal, mechanical, coating, swelling, and hydrophobic properties were investigated. The UV‐curing behavior was investigated using real‐time IR, and the overall double bond conversion was more than 90%. This biobased UV‐curable cardanol‐based diluent shows a promise in “green + green” materials technologies. [ABSTRACT FROM AUTHOR]