Search

This study successfully developed a bio-based, photocurable, anionic–nonionic dual-functional chain extender, and sulfonated cardanol-based polyethylene glycol (SCP), derived from renewable resources—cardanol and polyethylene glycol—for application in waterborne polyurethane dispersions (WPUDs). Utilizing SCP as a chain extender, WPUDs were prepared through a typical acetone process with poly(butylene adipate) (PBA), isophorone diisocyanate (IPDI), and ethylene diamine (EDA) at a constant NCO/OH ratio of 1:1. This research focused on the effects of polyethylene glycol molecular weight and SCP dosage on the particle size, stability, and film-forming properties of the WPUD. Optimal dispersion stability and film-forming performance were achieved with a polyethylene glycol molecular weight of 1500 and a PBA to SCP molar ratio of 4:1, yielding a particle size of 0.326 ± 0.010 μm and excellent storage stability over six months. The resulting WPU coatings exhibited a tensile strength of 11.4 MPa, which increased to 16.8 MPa after UV irradiation owing to the formation of a semi-interpenetrating network via the photopolymerization of cardanol's unsaturated side chains. UV cross-linking also enhanced water resistance, reducing the water absorption rate (WAR) from 18.68% to 4.21% and the water vapor transmission rate (WVTR) from 6.59 × 10−5 g·m⁻¹·Pa⁻¹·d⁻¹ to 2.26 × 10⁻⁵ g·m⁻¹·Pa⁻¹·d⁻¹, while also improving thermal stability. These findings demonstrate that SCP offers a sustainable and effective solution for developing high-performance WPU coatings. [ABSTRACT FROM AUTHOR]

Poly(vinyl chloride) (PVC) is a widely employed plastic across diverse industries and is often associated with plasticizers, additives that decrease the inherent rigidity and brittleness of the material. Conventional phthalate‐based plasticizers raise substantial toxicity concerns, encouraging the exploration of bio‐based alternatives. One such alternative is the inedible oil, cashew nutshell liquid (CNSL), mainly composed of cardanol and cardol. Recent efforts have focused on developing a cardanol‐based PVC plasticizers but the isolation of cardanol involves time‐consuming, energy‐intensive, and costly steps, limiting its market competitiveness. This study aims to assess for the first time, the efficiency of cardol esters, synthesized using acetic acid and different fatty acids (octanoic acid and myristic acid), in order to evaluate the influence of the alkyl chain on plasticizer properties. The chemical structures of these plasticizers were fully characterized by 1H NMR spectroscopy, and the mechanical properties and thermal behavior of PVC films plasticized with these additives were investigated. Finally, the endocrine activity was evaluated for cardol and cardanol acetates. [ABSTRACT FROM AUTHOR]

Objectives: To analyze the incorporation of cardanol trimethacrylate monomer (CTMA), derived from the cashew nut shell liquid, as a substitute for Bis-GMA in acrylic resins formulations and its effect on experimental resin composites’ physicochemical and mechanical properties. Materials and methods: The intermediary cardanol epoxy was synthesized via cardanol epoxidation, followed by the synthesis of CTMA through methacrylic anhydride solvent-free esterification. Experimental resin composites were formulated with an organic matrix composed of Bis-GMA/TEGDMA (50/50 wt %) (control). CTMA was gradually added to replace different proportions of Bis-GMA: 10 wt % (CTMA-10), 20 wt % (CTMA-20), 40 wt % (CTMA-40), and 50 wt % (CTMA-50). The composites were characterized by degree of conversion, water sorption and solubility, viscosity, thermogravimetric analysis, dynamic mechanical analysis, flexural strength and elastic modulus. Data were analyzed with one-way ANOVA and Tukey’s post-hoc test (α = 0.05), except for water sorption data, which were analyzed by Kruskall-Wallis and Dunn’s method. Results: CTMA-based and control composites did not show statistically significant differences regarding degree of conversion, flexural strength and elastic modulus. CTMA reduced the viscosity and solubility compared to the Bis-GMA-based composite. The CTMA-40 and CTMA-50 exhibited significantly lower water sorption compared to the control. Also, acceptable thermal stability and viscoelastic properties were obtained for safe use in the oral cavity. Conclusions: Incorporating CTMA into composites resulted in similar chemical and mechanical properties compared to Bis-GMA-based material while reducing viscosity, water sorption and solubility. Clinical relevance: CTMA could be used as a trimethacrylate monomer replacing Bis-GMA in resin composites, thereby minimizing BPA exposure. [ABSTRACT FROM AUTHOR]

In this study, a novel bio-based acrylic monomer derived from cardanol was synthesized and used in order to prepare acrylic copolymers that can be applied as thermoplastic polymers alone initially and then curable with the help of some driers to get a crosslink network similar to thermosetting polymers with their hydrophobic long alkyl chains having double bonds in their chemical structure. The synthesized polymers have the ability to be used in the paint or varnish formulations with or without paint driers. The synthesized monomers and polymers were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectroscopy (1H NMR). Thermal properties of the polymers and obtained coatings therefrom were studied by differential scanning calorimeter (DSC) and thermal gravimetric analysis (TGA). The varnish's thermal and coating characteristics, such as its adhesion, gloss, hardness, salt spray resistance, and touch and hard drying times, were examined and analyzed. The results showed that the bio-based cardanol moieties improved the coatings' resistance to chemicals and saltwater exposure as well as their thermal and mechanical characteristics through the incorporation aromatic and long linear alkyl chains. The block copolymers with cardanol units were used both on its own to produce thermoplastic polymeric films and in conjunction with driers to get thermoset crosslinking networks. The contact angle of thermoset polymeric films with driers measured as 77° but in case of thermoplastic blank polymer, it was 61°. Furthermore, the Tg of blank polymer was 13.37 °C, but with the addition of 10% cardanol units and a small amount of driers, the Tg was increased to 53.12 °C. [ABSTRACT FROM AUTHOR]

Biodegradable polymers are getting attention as renewable alternatives to petroleum-based plastics due to their environmental benefits. However, improving their physical properties remains challenging. In this work, biodegradable biopolymers (PVA-PCD) were fabricated by chemically crosslinking petroleum-based polyvinyl alcohol (PVA) with biomass-derived cardanol-based polyols (PCD). Biopolymers were characterized using various techniques, including Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and swelling tests. Cardanol, the raw material, was converted into polyols via epoxidation followed by hydroxylation. FT-IR analysis confirmed that PVA-PCD biopolymers were crosslinked between the hydroxyl groups of PVA and PCD and the aldehydes of crosslinker glutaraldehyde (GLU), accompanied by the formation of acetal groups with ether bridges. XRD showed that the crystallinity of crosslinked polymers decreased, indicating that crosslinking occurs disorderly. TGA exhibited that GLU significantly improved the thermal stabilities of PVA and PCD-PVA polymers, as evidenced by increased decomposition temperatures. On the other hand, the effect of PVA/PCD ratios was minor on biopolymers' thermal stabilities. Swelling tests revealed that increased crosslinking density decreased the swelling ratio, suggesting that PVA-PCD biopolymers become more hydrophobic with high brittleness, high strength, and low swelling capacity. In summary, this study demonstrates that PVA-PCD biopolymers fabricated from biomass-derived materials have potential for various applications, such as biodegradable materials and sustainable packaging. [ABSTRACT FROM AUTHOR]

A novel epoxy plasticizer (HCEP) with a hyperbranched polyglycerol structure was synthesized using reduced glycerol and cashew phenol as raw materials. Then it was grafted onto poly(vinyl chloride) (PVC) through click reaction to form self‐plasticized PVC. The structure of the product was characterized with various methods. The effects of the degree of internal plasticizer substitution on the properties of PVC were tested through dynamic mechanical, mechanical property, and thermogravimetric analyses. The amorphous dendritic structure of HCEP effectively enhances the free volume of grafted PVC, leading to a reduction in the glass transition temperature and a significant enhancement in flexibility at room temperature. The maximum elongation at break is 289.89%. The grafting of plasticizers onto PVC avoids the leaching of plasticizers during usage, providing a viable solution for reducing reliance on phthalate‐based plasticizers. [ABSTRACT FROM AUTHOR]

Bio‐based antioxidants have garnered attention for their sustainability and environmental benefits. In this study, we designed and synthesized three cardanol‐piperidine derivatives (HSs) by utilizing hydrogenated cardanol (HC) and piperidine derivatives to improve the aging inhibition of polypropylene (PP). These bio‐based antioxidants were intended as eco‐friendly alternatives to conventional synthetic antioxidants. The impact of these HSs on the thermal stability, thermo‐oxidative stability, and light stability of PP was thoroughly evaluated. The results unveiled that after 5 h of interaction with 2,2‐diphenyl‐1‐picrylhydrazyl free radical, HSs exhibited a remarkable over 5‐fold increase in free radical scavenging efficiency as compared to HC. Moreover, the addition of HSs significantly increased the oxidation induction time and the initial oxidation temperature compared to pristine PP. After photo‐oxidative aging and thermo‐oxidative aging, the HS‐dosed PP demonstrated remarkable retention of elongation at break, reaching more than 72% and 69%. From the comparison with physical mixtures and the density functional theory calculations, an intramolecular synergism mechanism is proposed. The intramolecular synergism between hydrogenated cardanol and piperidine derivatives may be the main reason for the inhibition of PP aging. Highlights: A method for constructing simultaneous efficient light, thermal, and oxygen stable polypropylene.The mechanism for achieving simultaneous stabilization of light, heat, and oxygen is the intramolecular synergy of phenol piperidine.The essence of intramolecular synergy of cardanol and piperidine derivatives is its' reduced hydrogen bond dissociation energy and energy gap. [ABSTRACT FROM AUTHOR]

The development of more recyclable materials is a key requirement for a transition towards a more circular economy. Thanks to exchange reactions, vitrimer, an attractive alternative for recyclable materials, is an innovative class of polymers that is able to change its topology without decreasing its connectivity. In this work, a bisphenol compound (VP) was prepared from saturated cardanol, i.e., 3−pentadecylphenol and vanillyl alcohol. Then, VP was epoxidized to obtain epoxide (VPGE). Finally, VPGE and citric acid (CA) were polymerized in the presence of catalyst TBD to prepare a fully bio−based vitrimer based on transesterification. The results from differential scanning calorimetry (DSC) showed that the VPGE/CA system could be crosslinked at around 163 °C. The cardanol−derived vitrimers had good network rearrangement properties. Meanwhile, because of the dynamic structural elements in the network, the material was endowed with excellent self−healing, welding, and recyclability. [ABSTRACT FROM AUTHOR]

Exploring sustainable approaches to replace petroleum-based chemicals is an ongoing challenge in reducing the carbon footprint. Due to the complexity and percentage variation in nature-generated molecules, which further varies based on geographical origin and the purification protocol adopted, a better isolation strategy for individual components is required. Agrowaste from the cashew industry generates phenolic lipid (cardanol)-rich cashew nutshell liquid (CNSL) and has recently shown extensive commercial utility. Cardanol naturally exists as a mixture of three structurally different components with C15-alkylene chains: monoene, diene, and triene. The separation of these three fractions has been a bottleneck and is crucial for certain structural designs and reproducibility. Herein, we describe the gram-scale purification of cardanol into each component using flash column chromatography within the sustainability framework. The solvent used for elution is recovered and reused after each stage (up to 82%), making it a cost-effective and sustainable purification strategy. This simple purification technique replaces the alternative high-temperature vacuum distillation, which requires substantial energy consumption and poses vacuum fluctuation and maintenance challenges. Three components (monoene 42%, diene 22%, and triene 36%) were isolated with good purity and were fully characterized by 1H and 13C NMR, GC-MS, HPLC, and FTIR spectroscopy. The present work demonstrates that greener and simpler strategies pave the way for the isolation of constituents from nature-sourced biochemicals and unleash the potential of CNSL-derived fractions for high-end applications.

Exploring sustainable approaches to replace petroleum-based chemicals is an ongoing challenge in reducing the carbon footprint. Due to the complexity and percentage variation in nature-generated molecules, which further varies based on geographical origin and the purification protocol adopted, a better isolation strategy for individual components is required. Agrowaste from the cashew industry generates phenolic lipid (cardanol)-rich cashew nutshell liquid (CNSL) and has recently shown extensive commercial utility. Cardanol naturally exists as a mixture of three structurally different components with C15-alkylene chains: monoene, diene, and triene. The separation of these three fractions has been a bottleneck and is crucial for certain structural designs and reproducibility. Herein, we describe the gram-scale purification of cardanol into each component using flash column chromatography within the sustainability framework. The solvent used for elution is recovered and reused after each stage (up to 82%), making it a cost-effective and sustainable purification strategy. This simple purification technique replaces the alternative high-temperature vacuum distillation, which requires substantial energy consumption and poses vacuum fluctuation and maintenance challenges. Three components (monoene 42%, diene 22%, and triene 36%) were isolated with good purity and were fully characterized by 1H and 13C NMR, GC-MS, HPLC, and FTIR spectroscopy. The present work demonstrates that greener and simpler strategies pave the way for the isolation of constituents from nature-sourced biochemicals and unleash the potential of CNSL-derived fractions for high-end applications. [ABSTRACT FROM AUTHOR]

Synthesis of bio-based monomers via continuous flow ozonolysis of cardanol using a simple tubular reactor is demonstrated. The direct ozonolysis of cardanol produces unique monomer 8-(3-hydroxyphenyl) octanal (HPOA) and heptanal along with several other oxidation products. Maximum 47% yield of HPOA with 54.3% conversion of cardanol was obtained at 0 °C in 9 s. The complete conversion of cardanol was obtained at the ozone to cardanol molar flow ratios greater than 2 at all temperatures varied in the range of -10 °C to 20 °C. Owing to large gas–liquid ratios, the mass transfer limitation for transfer of ozone from gas to liquid was negligible; however, the extent of axial dispersion in the liquid phase was significant at lower liquid flow rates. The non-ideal behavior was incorporated in the axial dispersion model to predict the conversion of cardanol. Examination of kinetic rates by both ideal plug-flow model and plug-flow with axial dispersion model revealed that the reaction is fast and is least influenced by the axial-dispersion in the reactor at prevailing operating conditions. The findings of the current study show that continuous flow technique enables a simple and safer synthesis of high-value bio-based monomers via ozonolysis of cardanol compared to traditional batch methods. [ABSTRACT FROM AUTHOR]

The green and environmentally friendly cardanol epoxy resin has a bright application prospect, but its insufficient thermal/mechanical properties seriously hinder its application. Adding nanoclay to polymer matrix is an effective method to enhance the thermal/mechanical properties of material, but the dispersion and compatibility of nanoclay in epoxy resin remain to be solved. In this work, active Girard's reagent clay (PG-clay) and non-active Girard's reagent clay (NG-clay) were prepared by using acethydrazide trimethylammonium chloride (Girard's reagent) as the modifier, and cardanol epoxy resin/G-clay nanocomposites were synthesized by the "clay slurry composite method". The results showed that both PG-clay and NG-clay were dispersed in the epoxy matrix in the form of random exfoliation/intercalation, which effectively improved the thermal/mechanical properties of the composites. Tg of the cardanol epoxy resin has raised from 19.8 °C to 38.1 °C (4 wt.% PG-clay). When the mass fraction of clay is 4%, the tensile strength of the non-reactive NG-clay increases by 128%, and the elongation at break also increases by 101%. Simultaneously, the active PG-clay can participate in the curing reaction of epoxy resin due to the amino group, forming a chemical bond between the clay layer and the resin matrix and establishing a strong interfacial force. The tensile strength of the composite is increased by 970%, and the elongation at break is also increased by 428%. This research demonstrates that the cardanol epoxy resin/G-clay nanocomposite stands as a highly promising candidate for bio-based epoxy resin materials. [ABSTRACT FROM AUTHOR]

BACKGROUND: Amine‐based deep eutectic mixtures composed of choline chloride and a DEA‐based hydrogen‐bond donor (HBD) can be used in various molar ratios such as 1:2, 1:3, 1:4, 1:5, 1:6 and 1:7 for isolation of cardanol from cashew nut shell liquid (CNSL). RESULTS: In this study, green techniques were created to extract cardanol from CNSL by utilizing a deep eutectic solvent (DES) based on diethanolamine with various molar ratios [hydrogen‐bond acceptor (HBA): HBD] of 1:2, 1:3,1:4,1:5, 1:6 and 1:7. To enhance cardanol's solubility in DES, promote phase separation, and increase cardanol yield, ethyl acetate (EA) and isobutyl methyl ketone (IBMK) could be utilized as co‐solvents. At temperatures ranging from 293 to 343.15 K and 1 atm, the density of various molar ratios of DES was determined. Additionally, the prepared DES pH behaviour as well as the relationship between pH and temperature were investigated. All investigated DES temperature increases caused a decrease in pH value. By using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC), similar molar ratios of amine‐based DESs were studied for their thermal stability in terms of decomposition temperature, mass loss and melting temperature. The melting temperature and thermal stability were both increased when the HBD increased. The thermal stability of DES, which mostly depends on intermolecular interactions, is greatly influenced by HBD. Finally, at T = 298.15 K and 1 atm, cardanol was extracted from 50 mL CNSL using different volumes of various molar ratios of DES (100 mL, 75 mL, 50 mL and 25 mL) together with 25 mL IBMK and 25 mL EA. The extracted cardanol was evaluated using Fourier transform infrared spectroscopy and gas chromatography–mass spectrometry. CONCLUSION: It was observed that the yields of cardanol from each prepared molar ratios ratio of 100 mL DES were 96.57%, 95.38% and 92.87%, respectively. In this study, the sigma potential and sigma profile of chosen HBA and HBD were determined using conductor‐like screening model for real solvents (COSMO‐RS), and the interactions between the molecules during the extraction process were analyzed. The findings demonstrated the viability of using the chosen DESs for the polyphenol extraction process. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Extractions of cashew nut shell liquid (CNSL) have always widely been carried out with non-environmentally friendly solvents. Hence, greener solvents are desired as alternative to currently used solvents. Herein, batch extractions of Nigerian CNSL with greener solvents: ethyl acetate and cyclohexane mixture in different ratios were investigated in hot and cold system and results compared with conventional solvent (petroleum ether). Compositional studies of the extracted CNSL and its isolated components were done with Fourier-Transformed Infrared (FTIR), Nuclear Magnetic Resonance (NMR) spectroscopy and Ultra High-Performance Liquid Chromatography-Mass Spectrometry (UHPLC-MS). Cost effectiveness analysis for the extraction solvents and methods was also investigated. It was revealed that ethyl acetate and ethyl acetate-cyclohexane mixture at cold and hot conditions recorded higher CNSL yields than previous reports even at a lower liquid-to-solid ratio. Chemical composition and component quantity extracted did not significantly change under hot or cold system. The present composition of the Nigerian CNSL contains unusually higher amount of anarcardic acid (79 %) and cardanol (14 %) than ever reported. Additionally, degree of unsaturation in the alkyl chain of the CNSL is in the order triene>monoene>diene in the anarcardic acid and cardanol components of the liquid. Cost effectiveness analysis at a kilogramme scale revealed that the order of greenness of extraction route based on solvent type, energy requirement and condition of extraction is ethyl acetate-solvent cold system> ethyl acetate-hot system> ethyl acetate-cyclohexane-system> cyclohexane system > pet. ether system.

Biodegradable polymers are getting attention as renewable alternatives to petroleum-based plastics due to their environmental benefits. However, improving their physical properties remains challenging. In this work, biodegradable biopolymers (PVA-PCD) were fabricated by chemically crosslinking petroleum-based polyvinyl alcohol (PVA) with biomass-derived cardanol-based polyols (PCD). Biopolymers were characterized using various techniques, including Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and swelling tests. Cardanol, the raw material, was converted into polyols via epoxidation followed by hydroxylation. FT-IR analysis confirmed that PVA-PCD biopolymers were crosslinked between the hydroxyl groups of PVA and PCD and the aldehydes of crosslinker glutaraldehyde (GLU), accompanied by the formation of acetal groups with ether bridges. XRD showed that the crystallinity of crosslinked polymers decreased, indicating that crosslinking occurs disorderly. TGA exhibited that GLU significantly improved the thermal stabilities of PVA and PCD-PVA polymers, as evidenced by increased decomposition temperatures. On the other hand, the effect of PVA/PCD ratios was minor on biopolymers’ thermal stabilities. Swelling tests revealed that increased crosslinking density decreased the swelling ratio, suggesting that PVA-PCD biopolymers become more hydrophobic with high brittleness, high strength, and low swelling capacity. In summary, this study demonstrates that PVA-PCD biopolymers fabricated from biomass-derived materials have potential for various applications, such as biodegradable materials and sustainable packaging.

Polyvinyl chloride (PVC) is a kind of plastic widely used in different industries, and it is a hard and brittle polymer that requires the use of plasticizers to improve processability. Phthalates are small molecule plasticizers of PVC, which are easy to volatilize and migrate while improving the processing properties of PVC. We propose alternatives based on phenolic resin prepolymer modified by cardanol (CPF), which were added to PVC as reactive plasticizer and can improve the processability of PVC. The effects of CPF on the rheological properties and migration resistance of plasticized PVC were studied, and the changes in the physical properties of blends were also discussed. The results showed that the viscosity of PVC melt can be reduced by two orders of magnitude by adding 30 wt% prepolymers at 180°C compared with PVC without CPF, which indicated that CPF can be used to reduce the processing temperature of PVC. The test results of migration resistance showed that the mass loss rate of the blend with 30 wt% prepolymers was less than 1 wt% after curing, however, the mass loss rate of the blend with 30 wt% dioctyl phthalate (DOP) was more than 12% after 5 days of testing. When the PVC/CPF mass ratio was between 60/40-70/30, the maximum values of tensile strength and elastic modulus are 64.4 MPa and 3.2 GPa, respectively, which showed the addition of CPF could significantly improve the tensile strength and elastic modulus of the blend system compared with PVC without CPF. Especially, the thermal stability of CPF is better than that of DOP, CPF exhibits the maximum thermal decomposition temperature (410°C), higher than that of DOP (170°C), which can adapt to higher processing temperature. [ABSTRACT FROM AUTHOR]

The bifunctional phenol (BBC) was derived from a sustainable resource, viz., cardanol, which is utilized to prepare benzoxazines using five structurally different amines with paraformaldehyde through Mannich condensation. The molecular structure of the synthesized benzoxazines were confirmed by FTIR and 1H-NMR spectral analyses. The curing behavior of the benzoxazines was studied using DSC and among all the synthesized benzoxazines, BBC-imp exhibits lower curing temperature of 224 °C than that of others. The thermal stability of all the polybenzoxazines were analyzed using TGA and poly(BBC-a) was found to be better thermally stable than that of other polybenzoxazines. Poly(BBC-tfma) showed the highest value of water contact angle of 152° and the lowest value of dielectric constant of 4.50. All the synthesized BBC-based polybenzoxazines possess good anti-corrosion property with a protection efficiency of 99%. Data obtained from different studies suggest that the polybenzoxazines developed in the present work can be considered for possible use in the form of sealants, encapsulants, adhesives and coatings for microelectronics and other industrial applications for better performance. [ABSTRACT FROM AUTHOR]

In this study, different amounts of SiO2 have been hybridized with cardanol-diaminodiphenylmethane (C-ddm) benzoxazine monomer to create superhydrophobic/superoleophilic cotton surfaces. Hybridization of silica with the C-ddm monomer has been carried out through both in-situ and ex-situ methods. Tetraethylorthosilicate (TEOS) was added as a silica precursor in the case of in-situ method, while pre-prepared mesoporous silica (SBA-15) was added separately in the case of ex-situ approach. Silane cross-linker was used in both approaches to create the organic–inorganic hybrid coating. Subsequently, the surface properties and characteristics of the modified cotton fabrics have been analyzed. The in-situ SiO2/poly(C-ddm) modified fabric showed a water contact angle (WCA) of 153° and a low sliding angle of 9°, which was higher than the ex-situ SBA-15/poly(C-ddm) modified fabric. Microscopic analysis showed that controlling the chain entanglement of the cardanol carbon chain was favored with the in-situ hybridization of silica. We found that the in-situ modified cotton fabric with 5% SiO2/poly (C-ddm) was effective in separating oil–water mixtures, with a separation efficiency of 99.1% and a flux value of 13,500 L/m2h. This study highlights the importance of a silica hybrid network in achieving superhydrophobic surfaces for oil–water separation applications, and suggests further investigations into the molecular arrangements involved in hybrid coatings. [ABSTRACT FROM AUTHOR]

Bio-based vitrimers present a promising solution to the issues associated with non-renewable and non-recyclable attributes of traditional thermosetting resins, showcasing extensive potential for diverse applications. However, their broader adoption has been hindered by the requirement for catalyst inclusion during the synthesis process. In this study, a cardanol-based curing agent with poly-hydroxy and tertiary amine structures was prepared by a clean synthetic method under the theory of click chemistry. The reaction of a cardanol-based curing agent with diglycidyl ether of bisphenol A formed catalyst-free, self-healing, and recyclable bio-based vitrimers. The poly-hydroxy and tertiary amine structures in the vitrimers promoted the curing of epoxy-carboxylic acid in the cross-linked network and served as internal catalysts of dynamic transesterification. In the absence of catalysts, the vitrimers network can achieve topological network rearrangement through dynamic transesterification, exhibiting excellent reprocessing performance. Moreover, the vitrimers exhibited faster stress relaxation (1500 s at 180 °C), lower activation energy (92.29 kJ·mol−1) and the tensile strength of the recycled material reached almost 100% of the original sample. This work offers a new method for preparing cardanol-based epoxy vitrimers that be used to make coatings, hydrogels, biomaterials, adhesives, and commodity plastics in the future. [ABSTRACT FROM AUTHOR]

Three biobased, CO2‐consuming, and carbamate‐groups‐containing surfactants (CC‐G, CC‐T, CC‐L) were synthesized separately by combination of Cardanol, CO2, Glycine sodium salt (G), Taurine sodium salt (T), and Lysine sodium salt (L). The chemical structures of CC‐G, CC‐T, CC‐L were confirmed by 1H NMR and IR spectra. Thermal properties of these surfactants were studied with TGA and DSC. Their critical micelle concentration (CMC) and surface tension at CMC (ΥCMC) in aqueous solution were obtained by surface tension and conductivity methods, respectively. The amount of excess concentration (Γmax) and the average occupied surface area (Amin) of three surfactants were calculated. Γmax of CC‐G, CC‐T and CC‐L was 2.35 × 10−7 mmol/m2, 2.23 × 10−7 mmol/m2, and 6.16 × 10−7 mmol/m2, separately. Amin of CC‐G was 0.71 nm2/mmol, CC‐T 0.74 nm2/mmol, CC‐L 2.70 nm2/mmol. The Krafft point, emulsification, and foaming power of these surfactants were investigated as well. The Krafft points were 0°C (CC‐G), 5°C (CC‐T) and 20°C (CC‐T). For CC‐G, the separation time of 10 mL double distilled water (DDW) was 43 min, CC‐T 40 min, and CC‐L 37 min. It was inferred from the calculated packing parameters that shape of the micelle of CC‐G, CC‐T were cylindrical in aqueous media, while CC‐L was spheroidal in aqueous media. [ABSTRACT FROM AUTHOR]

Plasticizers are widely used in poly(vinyl chloride) (PVC), polylactic acid (PLA), thermoplastic starch (TPS), and other modified powder materials to enhance the flowability, flexibility, and processability of macromolecules. Because of the reprotoxicity of phthalates in animals and humans, certain phthalates have recently been banned in the United States and Europe. Biobased plasticizers from green biomass–derived renewable resources with low toxicity are expected to be a substitute for phthalates. Among a variety of newly developed biobased monomers, cardanol, and isosorbide are the two most promising materials because of their unique structural features. This review summarizes the research progress of cardanol‐ and isosorbide‐based plasticizers with synergistic effects of plasticization, thermal stabilization, and anti‐migration. By summarizing and analyzing the relationship between molecular structure of plasticizer and plasticizing performance, this review can provide theoretical guidance for future research on the design of isosorbide‐ and cardanol‐based plasticizers. Highlights: Biobased plasticizers with low toxicity are expected to replace certain phthalates.The plasticizing effect of single biobased plasticizer is not good.Biobased plasticizer with synergistic effects is required.There exists the trade‐off effect between the molecular weight and the compatibility.Epoxidized isosorbide ester can be used as a heat stabilizer. [ABSTRACT FROM AUTHOR]

ABSTRACT: The objective of this study was to compare cashew nutshell extract (CNSE) to monensin and evaluate changes in in vitro mixed ruminal microorganism fermentation, nutrient digestibility, and microbial nitrogen outflow. Treatments were randomly assigned to 8 fermenters in a replicated 4 × 4 Latin square design with 4 experimental periods of 10 d (7 d for diet adaptation and 3 d for sample collection). Basal diets contained 43.5:56.5 forage: concentrate ratio and each fermenter was fed 106 g of DM/d divided equally between 2 feeding times. Treatments were control (CON, basal diet without additives), 2.5 μM monensin (MON), 0.1 mg CNSE granule/g DM (CNSE100), and 0.2 mg CNSE granule/g DM (CNSE200). On d 8 to10, samples were collected for pH, lactate, NH3-N, volatile fatty acids (VFA), mixed protozoa counts, organic matter (OM), and neutral detergent fiber (NDF) digestibility. Data were analyzed with the GLIMMIX procedure of SAS. Orthogonal contrasts were used to test the effects of (1) ADD (CON vs. MON, CNSE100, and CNSE200); (2) MCN (MON vs. CNSE100 and CNSE200); and (3) DOSE (CNSE100 vs. CNSE200). We observed that butyrate concentration in all treatments was lower compared with CON and the concentration for MON was lower compared with CNSE treatments. Protozoal population in all treatments was lower compared with CON. No effects were observed for pH, lactate, NH3-N, total VFA, OM, or N utilization. Within the 24-h pool, protozoal generation time, tended to be lower, while NDF digestibility tended to be greater in response to all additives. Furthermore, the microbial N flow, and the efficiency of N use tended to be lower for the monensin treatment compared with CNSE treatments. Overall, our results showed that both monensin and CNSE decreased butyrate synthesis and protozoal populations, while not affecting OM digestibility and tended to increase NDF digestibility; however, such effects are greater with monensin than CNSE nutshell.

This study comprehensively examines recent developments in bio-epoxy resins and their applications in composites. Despite the reliability of traditional epoxy systems, the increasing demand for sustainability has driven researchers and industries to explore new bio-based alternatives. Additionally, natural fibers have the potential to serve as environmentally friendly substitutes for synthetic ones, contributing to the production of lightweight and biodegradable composites. Enhancing the mechanical properties of these bio-composites also involves improving the compatibility between the matrix and fibers. The use of bio-epoxy resins facilitates better adhesion of natural composite constituents, addressing sustainability and environmental concerns. The principles and methods proposed for both available commercial and especially non-commercial bio-epoxy solutions are investigated, with a focus on promising renewable sources like wood, food waste, and vegetable oils. Bio-epoxy systems with a minimum bio-content of 20% are analyzed from a thermomechanical perspective. This review also discusses the effect of incorporating synthetic and natural fibers into bio-epoxy resins both on their own and in hybrid form. A comparative analysis is conducted against traditional epoxy-based references, with the aim of emphasizing viable alternatives. The focus is on addressing their benefits and challenges in applications fields such as aviation and the automotive industry. [ABSTRACT FROM AUTHOR]

This paper describes the synthesis of NIPU by using cardanol as starting material. A cardanol formaldehyde oligomer was first prepared through the reaction of cardanol and formaldehyde, catalyzed by citric acid. The resulting oligomer was then subjected to epoxidation with m-chloroperbenzoic acid to obtain an epoxide compound, which was subsequently used to fix carbon dioxide (CO2) and form a cyclic carbonate. Using this cyclic carbonate, along with an amine, cardanol-based isocyanate polyurethane (NIPU) was prepared. Different characterization methods, such as Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), and thermogravimetric analysis (TGA), were used to confirm the synthesis of the four intermediate products and NIPU in the reaction process. This study highlights the promise of bio-based NIPU as a sustainable alternative in a number of applications while offering insightful information on the synthesis and characterization of the material. [ABSTRACT FROM AUTHOR]

Biomass resources possessed the advantages of being natural, renewable, abundant, inexpensive, and easy to degrade. Therefore, fabricated bio‐based UV‐curable materials have gradually attracted much more attention, which meet the requirements of sustainable development and save petrochemical resources. In this paper, cardanol was modified to synthesize radical reactive diluent and hybrid reactive diluent by a facial method and was used to adjust the viscosity and reduce the volume shrinkage of UV‐curable epoxy acrylic resin. The structure–activity properties and UV‐curing kinetics of the obtained UV‐curable materials were clarified, and the anti‐shrinkage mechanism was also explored. In addition, the obtained cardanol‐based materials were compared with petroleum based diluent methyl methacrylate (MMA) and application for UV‐curable coatings. The volume shrinkage of the cardanol‐based reactive diluents was 3.5% and 2.1%, respectively, which were lower than MMA (4.6%). The CC conversion of the cardanol‐based reactive diluent exhibited the highest value of 79.6%. This work provided a specific theoretical basis for the subsequent design and application of bio‐based UV‐curable resins. It is of certain significance to the alleviation of the shortage of petrochemical resources and the sustainable development of the UV‐curable coating industries. [ABSTRACT FROM AUTHOR]

The objective of this study was to compare cashew nutshell extract (CNSE) to monensin and evaluate changes in in vitro mixed ruminal microorganism fermentation, nutrient digestibility, and microbial nitrogen outflow. Treatments were randomly assigned to 8 fermenters in a replicated 4 × 4 Latin square design with 4 experimental periods of 10 d (7 d for diet adaptation and 3 d for sample collection). Basal diets contained 43.5:56.5 forage: concentrate ratio and each fermenter was fed 106 g of DM/d divided equally between 2 feeding times. Treatments were control (CON, basal diet without additives), 2.5 μ M monensin (MON), 0.1 mg CNSE granule/g DM (CNSE100), and 0.2 mg CNSE granule/g DM (CNSE200). On d 8 to10, samples were collected for pH, lactate, NH 3 -N, volatile fatty acids (VFA), mixed protozoa counts, organic matter (OM), and neutral detergent fiber (NDF) digestibility. Data were analyzed with the GLIMMIX procedure of SAS. Orthogonal contrasts were used to test the effects of (1) ADD (CON vs. MON, CNSE100, and CNSE200); (2) MCN (MON vs. CNSE100 and CNSE200); and (3) DOSE (CNSE100 vs. CNSE200). We observed that butyrate concentration in all treatments was lower compared with CON and the concentration for MON was lower compared with CNSE treatments. Protozoal population in all treatments was lower compared with CON. No effects were observed for pH, lactate, NH 3 -N, total VFA, OM, or N utilization. Within the 24-h pool, protozoal generation time, tended to be lower, while NDF digestibility tended to be greater in response to all additives. Furthermore, the microbial N flow, and the efficiency of N use tended to be lower for the monensin treatment compared with CNSE treatments. Overall, our results showed that both monensin and CNSE decreased butyrate synthesis and protozoal populations, while not affecting OM digestibility and tended to increase NDF digestibility; however, such effects are greater with monensin than CNSE nutshell. [ABSTRACT FROM AUTHOR]

The development of a heat stabilizer with good thermal stability, plasticizing performance, and migration resistance for polyvinyl chloride (PVC) is still a notable challenge. In this work, two bio-based heat stabilizers, epoxidized cardanol oleate (ECD-OA) and epoxidized cardanol myristate (ECD-MA), were designed and synthesized with different lengths of their alkyl chains and different epoxy contents to provide outstanding compatibility with PVC. After confirming the chemical structures of ECD-OA and ECD-MA by proton nuclear magnetic resonance and Fourier-transform infrared spectroscopy, the thermal stabilizing effects of both epoxidized cardanol esters were compared with those of the traditional CaSt2/ZnSt2 stabilizer and bio-based epoxidized soybean oil. Then, the effects of four different heat stabilizers on the mechanical, thermal, rheological, and optical properties of PVC films were fully studied. The results suggested that the ECD-MA showed the best thermal stability, and the PVC/30DOP/5ECD-MA film did not turn black after 2 h of thermal aging at 200 °C. In addition, the ECD-MA had good compatibility with PVC, and it had a synergistic plasticizing effect, which caused the film to have a high ductility and tensile strength (320.1% and 19.8 MPa, respectively). [ABSTRACT FROM AUTHOR]

In the current work, an effort has been made to create polymer composite materials using polybenzoxazine (PBz), which is synthesis from sustainable natural ingredients like furfurylamine (Fu), cardanol (Ca) and reinforced with granite dust made from industrial waste. Varied analytical approaches were used to examine the thermal, morphological, chemical structure, flame retardant and electrical properties of Ca-Fu-PBZ composites reinforced with granite dust at varied weight percentages (5, 10, 15 and 20 wt%). According to the weight percentage concentration of granite dust, the differential scanning calorimetry (DSC) data suggest that the value of Tg increased from 105 to 139°C. A pure Ca-Fu-PBZ benzoxazine matrix was found to have a dielectric constant of 3.97 at 1 MHz. Whereas 5, 10 and 20 wt percentages of reinforced Ca-Fu-PBZ composites with granite dust had dielectric constants of 3.54, 3.05, 2.51 and 2.02 at 1 MHz, respectively. For granite dust reinforced Ca-Fu-PBZ polybenzoxazine composites, the value of the limiting oxygen index (LOI) determined for the char yield obtained thermogravimetric analysis (TGA) shows greater values than those of the neat Ca-Fu-PBZ matrices. Using water contact angle, the hydrophobic behavior of polybenzoxazine composites reinforced with granite dust was investigated, and it was concluded that the hydrophobic behavior increased with the weight % of granite dust. Data from several investigations show that the thermally stable electrical insulation applications can employ the granite dust reinforced sustainable cardanol-furfurylamine based polybenzoxazine composites as potting compounds, sealants and composites. [ABSTRACT FROM AUTHOR]

Cardanol is a natural material that acts to stabilize asphaltenes in crude oil. However, its derivative, polycardanol, obtained via cationic polymerization, has divergent behaviour, with reports of its acting both as asphaltenes stabilizer and flocculant. Recently, it was demonstrated that the reaction conditions influence the conversion rates, structures, and molar masses of the products from synthesizing polycardanol initiated with BF3 · O(C2H5)2. Seeking to elucidate the influence of these variables on the phase behaviour of asphaltenes, in this work six products, previously synthesized and characterized, had their performance evaluated by asphaltenes precipitation onset, using n‐heptane titration and monitoring by near‐infrared spectroscopy, using asphaltenes model systems (C5I and C7I) at 1.00 wt./vol.% in toluene. All the products had the ability to flocculate asphaltenes and have potential for deasphalting process. Flocculation efficiency increased with rising molar mass, higher reaction conversion degree, and presence of lateral hydrocarbon chains. The most efficient structures were not affected by the presence of unreacted cardanol. This indicated that the reaction does not require a purification step. Aged cardanol was also able to produce flocculant polymer, indicating that the distillation of cardanol is not required. The cost to obtain a product without needing reagent distillation becomes lower. [ABSTRACT FROM AUTHOR]

Aspen and poplar are the least required types of wood in the Russian Federation, whose stock is continually expanding. Such wood can be used as a substitute for valuable hardwood, but in this case the strength must be almost doubled while achieving stability in shape and size. Treatment with acetic anhydride, polyvinyl alcohol, polyethylene glycol, or hydrothermal care are the most common methods for maintaining the volumetric stability of the wood. Treatment with phenol- and urea-formaldehyde monomers, oligomers, and resins is typically done for strength improvement. The stabilization of the dimensional parameters is especially critical for pressed wood, which has 8 times greater swelling in water than raw wood. Cardanol was chosen as a modifier. It can be derived from cashew nutshell liquid or synthesized. The established technique for impregnating wood with cardanol includes 2–3 % acetic acid, followed by heat treatment at 140–150 °С for 6–8 hours. During this process, cardanol polymerizes with components of the lignocarbohydrate complex of the wood, which does not only improve its characteristics but also provides form and size stability in an environment with changeable humidity. A Mettler Toledo DSC 823e/700 differential scanning calorimeter was used to examine the kinetics. Heat fluxes were measured in 30 µl sealed steel crucibles that could sustain steam pressure up to 15 MPa. At a heating rate of 10 °C/min, the heat flow curve showed an exothermic peak with a maximum temperature of 150.7 °C. Aspen wood with 15 % cardanol content has a compressive strength along the fibers of 69 MPa, a volume swelling limit of 2.6 %, and a moisture absorption limit of 18 %. The ultimate water absorption and ultimate volumetric swelling of wood impregnated with cardanol are comparable to the relevant indications of the modified wood brands Accoja, Belmadur, and Thermowood. For citation: Shamaev V.A., Shishlov O.F. Hardening and Stabilization of Volumetric Properties in Aspen and Poplar Wood with Cardanol. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 3, pp. 155–161. (In Russ.). https://doi.org/10.37482/0536-1036-2023-3-155-161

The underwater curing agents have demonstrated promising potential in various applications, especially in underwater repair engineering, yet have proven considerable challenging. Here, we report a cardanol-based curing agent for epoxy resin that achieves robust adhesion to steel and concrete substrates both in air and underwater. Cardanol, paraformaldehyde, and m-phenyldimethylamine are selected as the polymeric monomers to synthesize curing agent by Mannich reaction in the absence of chemical cross-linker agents. The coating is completely cured within 46 ± 1 min in air and 54 ± 2 min under water with an adhesion of 0 or 1 and a hardness of 5H. The impact strength, shear strength, and tensile strength of coating on underwater concrete were 9.58 ± 0.41 kJ·m−2, 13.1 ± 0.3, and 10.5 ± 0.2 MPa, respectively, demonstrating exceptional flexibility and mechanical strength as well as favorable hydrophobicity. This work paves the way for the rehabilitation of underwater drainage network for urban infrastructure and water conservancy projects.

Cashew nut shell liquid (CNSL), obtained as a byproduct of the cashew industry, represents an important natural source of phenolic compounds, with important environmental benefits due to the large availability and low cost of the unique renewable starting material, that can be used as an alternative to synthetic substances in many industrial applications. The peculiarity of the functional groups of CNSL components, such as phenolic hydroxyl, the aromatic ring, acid functionality, and unsaturation(s) in the C15 alkyl side chain, permitted the design of interesting nanostructures. Cardanol (CA), anacardic acid (AA), and cardol (CD), opportunely isolated from CNSL, served as building blocks for generating an amazing class of nanomaterials with chemical, physical, and morphological properties that can be tuned in view of their applications, particularly focused on their bioactive properties. [ABSTRACT FROM AUTHOR]

Cardanol, a waste from the food industry and widely produced (1 Mt/y), has been used as a chain stopper during the polycondensation of short oil alkyd resins in order to replace benzoic acid. Then, phosphorylated cardanol has been added in order to both reduce solvent content and bring flame-retardant (FR) properties to the alkyd resins. The renewable carbon content of the formulations has been increased up to 23%. The impact of the introduction of phosphorylated cardanol molecules on the drying time and flexibility has been studied as well as the thermal and flame-retardant properties by differential scanning calorimeter, thermogravimetric analysis and pyrolysis-combustion flow calorimeter. The most effective flame-retardant coating that was associated with excellent FR properties and excellent coating properties has been obtained with phosphate-cardanol added at 2%wt of P. Indeed, the film properties were closed to the classical alkyd resin, the solvent content was reduced by 50% and the pHRR decreased by 42% compared to the reference alkyd resin.

Polymers are currently in the limelight. Phenolic resin is one of the polymer products obtained from the polymerization process, either from natural or synthetic sources. One of the natural compounds that can be applied to polymers is cardanol. This study aimed to synthesize cardanol-based acetaldehyde novolac resin from Cashew Nut Shell Liquid (CNSL). Isolation of cardanol from CNSL was done by liquid-liquid extraction method with acetone and purified by gravity column chromatography in a mixture of n-hexane and ethyl acetate in a ratio of 9:1. HPLC analysis showed that cardanol compounds had aliphatic chains with different levels of saturation and the yield was 18.48%. The cardanol-acetaldehyde novolac resin was synthesized through a condensation polymerization reaction with a cardanol-acetaldehyde mole ratio (1:0.5), using HCl as a catalyst. FTIR and 1H-NMR analysis were employed to identify the novolac resin structure. The product was a brownish-orange solid with a yield of 12.80 mg (40%) and followed ortho-ortho substitution. Cardanol is one of the natural phenol sources that might be utilized to manufacture novolac resins.

In the present investigation, the mechanical and thermal properties of a hybrid epoxy matrix composite fabricated with natural hemp, rice husk fibers, synthetic E-glass fiber and phenolic cardanol bio-resin by hand lay-up process were studied. The composites were fabricated with varying weight concentrations of fillers and matrix. In this work, the effect of natural fiber and cardanol on the fiber-matrix bonding and the hybrid composite stability were studied. Tensile, flexural, Shore D hardness, Izod impact absorption, TGA, and DTA properties were studied. The results indicated improved thermal and dimensional stability with enhanced tensile performance of the specimens due to the superior bonding ability of cardanol leading to better fiber encapsulation. Cardanol also enhances the biodegradability of the hybrid composite.

In this study, we have developed bio-based nanocomposites of polybenzoxazine from bio-benzoxazine resins (C-Fu-BZ and E-Fu-BZ) that are armored with varying weight percentages (1, 3, 5, and 7 wt%) of functionalized silica from cow manure (FCMS). These materials are intended for applications that call for high performance materials. Fourier-transform infrared was used to determine the molecular structure of benzoxazines (FTIR). Eugenol-based matrices and composites had superior heat stability than bio-benzoxazines (C-Fu-PBZ and E-Fu-PBZ) and bio-benzoxazine composites in terms of morphology and water contact angle. 1 weight percent of bio-silica-loaded C-Fu-PBZ at 1 MHz was 3.34 for the composite. The 3, 5, and 7 weight percents of FCMS embedded C-Fu-PBZ composites are also discovered to be 2.86, 2.27, and 1.62, respectively. The dielectric constant values for E-Fu-PBZ and 1, 3, and 5 weight percent of FCMS-loaded E-Fu PBZ composites are 4.73, 4.05, 3.57, 2.82, and 2.16 respectively. The contact angle for C-Fu-PBZ reinforced with 1 wt% FCMS is 96°, whereas the contact angles for C-Fu-PBZ reinforced with 3, 5, and 7 wt% bio-silica were found to be 103°, 114°, and 126°, respectively. The E-Fu-PBZ biocomposites values are similarly 86°, 91°, 99°, and 108°. The cardanol-based polybenzoxazine bio-composites have greater values of water contact angle than the eugenol-based polybenzoxazines among the C-Fu-PBZ and E-Fu-PBZ matrices and FCMS-loaded composites. The FCMS distributions and uniform dispersion in the C-Fu-PBZ and E-Fu-PBZ polybenzoxazine matrices were seen in the TEM pictures. Data obtained from different studies for bio-based benzoxazines (C-Fu-BZ and E-Fu-BZ) indicate that the polybenzoxazine matrices and their composites have excellent thermal stability and good hydrophobic behavior suitable to employ them for coatings materials for different industrial products. [ABSTRACT FROM AUTHOR]

In order to explore effective strategies to fabricate main‐chain polybenzoxazine (PBZ) thermosetting resin for structural material applications, here, five PBZ with different molecular structures, that is, poly(Co‐ddm), poly(Co‐BPA‐ddm‐Co)main, poly(Ph‐BPA‐ddm‐Co)main, poly(Ph‐BPA‐ddm‐Ph)main and poly(Ph‐ddm) were designed, synthesized and compared by introducing unsaturated fatty chains through the Mannich reaction with cardanol. The structure and properties of five PBZ with different structure were systematically investigated by using Fourier transform infrared (FTIR), NMR, water absorption and mechanical tests. FTIR and NMR tests indicated that five PBZ with different molecular structures were successfully synthesized. The mechanical tests indicated that the impact strength of the double‐capped cardanol‐based main‐chain PBZ was 243% higher than that of the traditional PBZ. The water absorption of main‐chain PBZ was higher than that of diamine PBZ, and the water absorption of poly(Ph‐BPA‐ddm‐Co)main was the lowest in the main‐chain PBZ. Based on the experimental results, five PBZ amorphous cells with different structures were successfully established. It indicated that the main chain PBZ showed better thermomechanical properties than the traditional diamine PBZ due to high crosslinking conversion and hydrogen bond density. Moreover, the modulus and glass transition temperature of the main chain structure containing unsaturated fatty chains did not decrease significantly. [ABSTRACT FROM AUTHOR]

Solvent extraction has been ubiquitously used to recover valuable metals from wastes such as spent batteries and electrical boards. With increasing demands for energy transition, there is a critical need to improve the recycling rate of critical metals, including copper. Therefore, the sustainability of reagents is critical for the overall sustainability of the process. Yet, the recycling process relies on functional organic compounds based on the hydroxyoxime group. To date, hydroxyoxime extractants have been produced from petrol-based chemical feedstocks. Recently, natural-based cardanol has been used to produce an alternative hydroxyoxime. The natural-based oxime has been employed to recover valuable metals (Ga, Ni, Co) via a liquid/liquid extraction process. The natural compound has a distinctive structure with 15 carbons in the alkyl tail. In contrast, petrol-based hydroxyoximes have only 12 or fewer carbons. However, the molecular advantages of this natural-based compound over the current petrol-based ones remain unclear. In this study, molecular dynamics simulation was employed to investigate the effect of extractant hydrocarbon chains on the extraction of copper ions. Two hydroxyoxime extractants with 12 and 15 carbons in the alkyl chain were found to have similar interactions with Cu2+ ions. Yet, a slight molecular binding increase was observed when the carbon chain was increased. In addition, lengthening the carbon chain made the extracting stage easier and the stripping stage harder. The binding would result in a lower pH in the extraction step and a lower pH in the stripping step. The insights from this molecular study would help design the extraction circuit using natural-based hydroxyoxime extractants. A successful application of cashew-based cardanol will improve the environmental benefits of the recycling process. With cashew-producing regions in developing countries, the application also improves these regions' social and economic sustainability. [ABSTRACT FROM AUTHOR]

To expand the application of natural resources in the green rubber industry and reduce the dependence of rubber additives on the non‐renewable petrochemical resources, a novel cardanol‐based natural rubber additive (silica‐s‐LPCGE) is prepared. Compared with the directly adding of silica and LPCGE, silica‐s‐LPCGE is assisted to form an effective interfacial interaction between the rubber matrix and the filler during rubber vulcanization by the immobilized LPCGE on silica surface, to improve the mechanical property and processability of styrene‐butadiene rubber (SBR)/silica‐s‐LPCGE composites. Meanwhile, with the introduce of silica‐s‐LPCGE, the aging resistance and migration resistance of the SBR composites are also improved obviously. The preparation of this novel multifunctional supported natural biomass processing additive provides a new possibility for the preparation of green rubber additives. [ABSTRACT FROM AUTHOR]

The industry has pursued efforts to minimize the use of fossil fuel-based processing oils in favor of naturally occurring nontoxic oils from renewable sources, such as vegetable oils. In this study, the feasibility of replacing naphthenic oil (NAPH)-based plasticizers in natural rubber (NR) compounds with oil originating from cashew nut shells was evaluated. Cardanol oil (Cdn), which is derived from decarboxylated cashew nut shell liquid, a byproduct of cashew nut production, was chemically modified by acetylation and named Cdn-A. The successful acetylation of Cdn with acetic anhydride was confirmed. The effects of Cdn and Cdn-A as plasticizers on the curing characteristics, thermal aging, and physical, mechanical, and dynamic properties of carbon black-filled NR compounds were then evaluated. Cdn acted as a co-activator for rubber vulcanization; by contrast, Cdn-A showed negligible effects on this process. Vulcanized Cdn- and Cdn-A-containing NR compounds exhibited improved abrasion and tear resistance compared with the reference compound containing NAPH, as well as antioxidant activity. The Cdn-added NR compound also demonstrated high elongation at break and toughness. The results collectively suggest that NR compounds containing Cdn exhibit properties suitable for tire tread applications requiring high grip characteristics. [ABSTRACT FROM AUTHOR]

Bio‐based epoxy polymer was prepared from cardanol derivatives, epoxy prepolymer and phenalkamine at room temperature without solvent. Chemical structures of cured epoxy polymers were analyzed by FT‐IR and 1H NMR spectroscopy. The drying, physical, thermal, optical, and mechanical properties of the epoxy polymers were investigated in terms of the composition of epoxy and amine compounds, molecular weight of the epoxy prepolymer, and the effect of post‐curing process. The resultant epoxy polymers showed flexible nature, thermal stability (e.g., thermal decomposition temperature of 300°C). Furthermore, the epoxy polymers possessed the anti‐microbial activity against Escherichia coli and Staphylococcus aureus The molecular weight of the epoxy prepolymer also strongly affected the drying property, suggesting that the drying time can be controlled by the molecular weight of the prepolymer. Thermal treatment of the polymers as post‐curing was effective approach to improve the hardness, thermal stability, and mechanical strength. Hence, this cardanol derivatives‐based novel epoxy polymer can be expected as highly green functional epoxy polymers for coating, film and resin applications. [ABSTRACT FROM AUTHOR]

Cardanol, a waste from the food industry and widely produced (1 Mt/y), has been used as a chain stopper during the polycondensation of short oil alkyd resins in order to replace benzoic acid. Then, phosphorylated cardanol has been added in order to both reduce solvent content and bring flame-retardant (FR) properties to the alkyd resins. The renewable carbon content of the formulations has been increased up to 23%. The impact of the introduction of phosphorylated cardanol molecules on the drying time and flexibility has been studied as well as the thermal and flame-retardant properties by differential scanning calorimeter, thermogravimetric analysis and pyrolysis-combustion flow calorimeter. The most effective flame-retardant coating that was associated with excellent FR properties and excellent coating properties has been obtained with phosphate-cardanol added at 2%wt of P. Indeed, the film properties were closed to the classical alkyd resin, the solvent content was reduced by 50% and the pHRR decreased by 42% compared to the reference alkyd resin. [ABSTRACT FROM AUTHOR]

In this work, the corrosion protection of 316L steel was promoted by an electro‐synthesized polymer obtained from the technical cashew nutshell liquid (t‐CNSL). Spectroscopic techniques confirmed the polymer formation. The polymer was dispersed in the ethyl acetate solvent and used to form coatings on 316L steel substrates. The coated samples were subjected to electrochemical tests in a saline environment. The coated electrode with poly(t‐CNSL) polymer was exposed to the corrosive medium for 24 days, and superior corrosion protection was observed compared with the uncoated sample. The open circuit potential measurements showed that the coated sample possessed a more positive corrosion potential when compared with the uncoated substrate. The electrochemical impedance spectroscopy results indicated that the coated electrode's polarization resistance (Rp) recorded ~1.0 MΩ cm2 after 24 days of exposure. A decrease in polarization resistance was observed with the exposure time due to the presence of micropores in the t‐CNSL coating. The polarization curves exhibited that the coated electrode with poly(t‐CNSL) has lower corrosion current density and less negative corrosion potential than the uncoated steel electrode. Therefore, t‐CNSL favors the manufacture of thin poly(t‐CNSL) coatings for corrosion protection purposes besides being a low‐cost material. [ABSTRACT FROM AUTHOR]

Cardanol/phenol-based foaming resol resins were prepared successfully by reacting formaldehyde with cardanol/phenol. Phenolic foams were fabricated with the above foaming resol resin and certain foaming agents. Two kinds of resol resins were characterized with Fourier transform infrared spectroscopy, rheological analysis and Scanning electron microscope. Meanwhile, the nonisothermal curing reactions of these resol resins were studied in detail using a dynamic Differential scanning calorimetry technique at a series of heating rates. The global activation energies of the reactions were determined with the Ozawa methods. The results indicated that the peak temperatures of the exothermic reactions and global activation energies of cardanol-based foaming resol resin were higher than those of phenol-based foaming resol resin, which indicated that the more complex molecular structure of cardanol-based foaming resol resin has a negative effect on the curing speed of resin. [ABSTRACT FROM AUTHOR]

Poly(vinyl chloride) (PVC) is a widely used plastics in different industries. It is an intrinsically hard and brittle polymer and requires the use of plasticizers to improve the processability. Commonly used phthalate‐based plasticizers have serious toxicity issues and we present alternatives based on epoxidized soybean oil (ESO) and epoxidized cardanol esters (ECEs). ECEs are synthesized from cardanol and three fatty acids (oleic, ricinoleic, and myristic) using 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide (EDC) as a coupling agent. Their structure and purity are confirmed by Fourier transform infrared spectroscopy (FTIR) and Nuclear magnetic resonance. Moreover, plasticized PVC films are prepared using a solvent‐free method. The replacement of 10 phr of ESO with 5 phr of ECE improves the plasticizing power due to the co‐solvency effect. Mechanical properties and thermal stability of plasticized PVC films are correlated with the chain length and the number of epoxy groups in ECE. The best plasticizing effect is observed for epoxidized cardanol‐myristate (ECD‐MA). ECD‐MA as a shorter‐chain secondary plasticizer is more compatible with ESO and allows higher conformational mobility of PVC chains. PVC/30ESO/5ECD‐MA polymer exhibits an exceptionally high initial thermal decomposition temperature (314.4°C) while preserving moderate ductility and tensile strength (263.4% and 23.3 MPa). Overall, this study highlights the potential applicability of ECD‐MA in combination with ESO as a sustainable, bio‐based plasticizer and heat stabilizer for flexible PVC products. [ABSTRACT FROM AUTHOR]

Moisture exposure during polyester processing can lead to degradation, resulting in the formation of carboxyl and hydroxyl end-groups. To preserve mechanical properties, thorough drying and the use of chain extenders like epoxy acrylates and isocyanates during extrusion are crucial for maintaining or enhancing molecular weight through in-situ reactions. Our study introduced epoxidized cardanol oleate (ECD-OA), containing epoxy and long-chain alkyl groups, as a potential chain extender, and compared its effectiveness with commercially available epoxidized cardanol glycidyl ether (cardolite NC514). Compared to neat PLA without chain extension, the addition of 1 phr ECD-OA resulted in an increase in the molecular weight (M w) of PLA from 15.3 × 104 g/mol to 17.1 × 104 g/mol, demonstrating a chain extension efficiency of 11.8 %. The melt flow rate of PLA decreased from 9.9 g/10 min to 5.0 g/10 min, and the initial thermal degradation temperature of PLA increased by 5.7 °C. Upon chain extension, there was a substantial increase in both the elongation at break and tear resistance of the PLA film. The results demonstrate that ECD-OA can extend PLA molecular chains through chemical reactions and promote entanglement with the long alkane chain, consequently enhancing the mechanical and thermal properties of PLA. Due to the enzyme's preference for biobased small molecules, the PLA film with the addition of a biobased chain extender is more prone to enzymatic degradation compared to neat PLA. To conclude, ECD-OA acts as a bio-based chain extender that improves the performance of PLA while also enhancing its biodegradability. [Display omitted] • Introduces ECD-OA as a bio-based PLA chain extender • Enhances PLA molecular weight and thermal degradation temperature by 5.7 °C • Improves mechanical properties, particularly elongation at break • Improves PLA performance while boosting its biodegradability [ABSTRACT FROM AUTHOR]

This study introduces a novel graphene/bio-based phthalonitrile nanocomposite with ultrahigh dielectric constant and excellent thermal stability. Specifically, a bio-based phthalonitrile resin (CPN) was synthesized by nucleophilic substitution between cardanol and 4-nitrophthalonitrile. Graphene sheets (GNS) were prepared by direct high-speed wet ball-milling exfoliation method. Then, CPN/GNS nanocomposites were prepared by a facile hot-press method and their structures, dielectric and thermal degradation behaviors were systematically discussed. The incorporation of GNS significantly improved the dielectric constant of CPN/GNS nanocomposites by 1096.80 % compared with that of phthalonitrile matrix. Thermal decomposition of CPN/GNS nanocomposite happened in the cleavages of weak C-N, C-O and C-C bond, with a stacking mechanism of main chain decomposition and the further carbonization of prior decomposition product by releasing NH 3 , CO 2 , CH 4 , C 6 H 6 , C 6 H 5 OH and H 2 O. CPN/GNS nanocomposites showed excellent thermal stabilities and flame reactance, with a T d5 % of over 400 °C, a char yield of 36 wt% at 800 °C and a limit oxygen index of above 32, respectively. CPN/GNS nanocomposite holds great promise as an environmentally friendly replacement for petroleum-based materials in high-temperature resistant dielectric applications. [Display omitted] • A bio-based phthalonitrile resin (CPN) was synthesized by nucleophilic substitution. • Graphene nanosheets (GNS) were prepared by direct high-speed wet ball-milling exfoliation method. • Dielectric constant of CPN/GNS nanocomposite was improved by 1096.80 % compared with that of phthalonitrile matrix. • CPN/GNS nanocomposite showed a T d5% of over 400 ℃ and limit oxygen index of above 32.. • Thermal decomposition mechanism of CPN/GNS nanocomposite is proposed. [ABSTRACT FROM AUTHOR]