Epoxidized Vegetable Oils Research Articles

Synthesis and evaluation of polymeric dispersant based on vegetable oils their application as cutting fluid

In this work, a novel vegetable oil-based polymeric agents were prepared by epoxidation of rapeseed oil (RO) and castor oil (CO) followed by ring opening reaction of epoxidized products, (epoxidized rapeseed oil and epoxidized castor oil) (ERO) and (ECO) with polyethylene glycol with different molecular weights (400, 600 and 10000 g/mole). The prepared polymers were characterized by 1H NMR, FTIR and GPC for determination of molecular weight. The properties of epoxidized vegetable oil (EVO) and Polymeric vegetable oils (polymeric dispersant of rapseed (PDR) and (polymeric dispersant of castor (PDC) were studied. The prepared polymers were employed as emulsifiers for metal working cutting fluids (MWCF) application.

New UV‐Curable Anticorrosion Coatings from Vegetable Oils

AbstractBio‐based epoxy resins are attracting widespread interest in the field of polymer thermosets as environmentally friendly building block. In the present study, the feasibility of applying UV‐curable epoxidized vegetable oils (EVOs) as anti‐corrosion coating is investigated. Rheological characterization of EVOs is carried out, and their viscosity‐shear relationship is evaluated. The cationic UV‐curing of EVOs successfully gives rise to crosslinked materials with a wide range of thermo‐mechanical properties, evaluated by differential scanning calorimetric analysis and dynamic thermal mechanical analysis. A high epoxy‐group conversion, ranging from 93% to 99%, is always obtained. The thermal stability and surface properties of the bio‐based coatings, such as, pencil hardness, adhesion, solvent resistance, and contact angle, are analyzed. Moreover, the corrosion protection effectiveness of the coatings is characterized by potentiodynamic polarization and electrochemical impedance spectroscopy measurements. In addition, field emission scanning electron microscopy is used to assess the samples morphology after corrosion tests.

The effect of epoxidized vegetable oil and phthalic anhydride as compatibilizers on properties of rubber seed shell/polypropylene composites

Numerous adverse effects are reported from excessive usage of synthetic polyolefins including major environmental concerns. Since then, the development of natural-based polymer composites is escalating, to replace the versatile conventional plastics that possess excellent mechanical and thermal properties. Rubber seed shell (RSS) is a novel and abundant natural-based substituent that is highly composed of hemicellulose and cellulose. In this work, we reported on the performance of RSS-filled polypropylene composites added with two different types of compatibilizers: epoxidized vegetable oil (EVO) and phthalic anhydride (PA). The composites were produced using a Haake internal mixer and a compression molding. The tensile, flexural, and impact properties of the composites were analyzed. Later, we investigated the thermal stability and water absorptivity of the composites. The mechanical, thermal, and water absorption properties of the RSS-filled composites deteriorated with increasing RSS loadings. For both EVO and PA-compatibilized systems, the mechanical properties were enhanced except for the elongation-at-break of the composites. PA-compatibilized composites recorded better thermal stability and water absorption resistance under ambient conditions compared to RSS composites with EVO. The qualitative structural evidence of the composites enhanced properties and deterioration were observed using a Zeiss Supra scanning electron microscope. As a novel natural filler, RSS has adequately proven its practicability in manufacturing environmentally friendly natural composites with acceptable mechanical and thermal properties.

Influence of the Presence of Disulphide Bonds in Aromatic or Aliphatic Dicarboxylic Acid Hardeners Used to Produce Reprocessable Epoxidized Thermosets.

The design of polymers from renewable resources with recycling potential comes from economic and environmental problems. This work focused on the impact of disulphide bonds in the dicarboxylic acids reactions with three epoxidized vegetable oils (EVOs). For the first time, the comparison between aromatic vs. aliphatic dicarboxylic acids, containing or not S–S bonds with EVOs was discussed and evaluated by dynamic scanning calorimetry. The obtained thermosets showed reprocessability, by the dual dynamic exchange mechanism. The virgin and reprocessed materials were characterized and the thermomechanical properties were compared. The thermosets derived from EVOs with high epoxy content combined with aromatic diacids containing disulphide bridges showed high glass transition values (~111 °C), high crosslink densities and good solvent stability.

Rapid self-healing, multiple recyclability and mechanically robust plant oil-based epoxy resins enabled by incorporating tri-dynamic covalent bonding

Novel bio-based epoxy resins with high tensile strength, rapid self-healing and excellent multiple recyclability were synthesized through thiol–epoxy “click” reaction between epoxidized vegetable oils and dithiol-functionalized boronic ester.

Recyclable, Repairable, and Reshapable (3R) Thermoset Materials with Shape Memory Properties from Bio-Based Epoxidized Vegetable Oils.

The preparation of thermosets based on epoxidized vegetable oils (EVOs) involved a peculiar attention in recent years; however, most of them cannot be recycled once cross-linked. In the present work, epoxy thermosetting resins like-vitrimers with dynamic disulfide covalent bonds were prepared by copolymerizing twelve EVOs with 2,2'-dithiodibenzoic acid, as hardener. Here, we show for the first time the reprocessability, repairability, and recyclability properties of EVOs thermosets. The 3R abilities were evaluated in correlation with the EVO epoxy contents, which influence the final thermo-mechanical properties of the recycled material. The virgin versus recycled materials' comparison was studied by FT-IR, DSC, TGA, and DMA, also comparing their swelling ability and high gel content. The study investigates, in addition, the excellent shape memory properties of the reprocessed EVOs/disulfide materials.

Sustainable Series of New Epoxidized Vegetable Oil-Based Thermosets with Chemical Recycling Properties.

This work reports for the first time the copolymerization studies of 11 newly synthesized epoxidized vegetable oils (EVOs) that reacted with a disulfide-based aromatic dicarboxylic acid (DCA) to produce thermoset materials with recyclability properties. These new EVOs' reactivity and properties were compared with those of the two commercial references: epoxidized linseed oil (ELO) and epoxidized soybean oil (ESO). The structure-reactivity correlation is proposed by differential scanning calorimetry (DSC) analysis, corroborating the epoxy content of EVO monomers, the initiator effect, the copolymerization reaction enthalpy, and the temperature range. The thermomechanical properties of the obtained thermosets were evaluated and discussed in correlation with the structure and reactivity of monomers by dynamic mechanical analysis (DMA), tensile testing, and thermogravimetric analysis (TGA). It has been found that the higher the EVO functionality, the higher is the reactivity, cross-linking density, and final performances, with tan δ values ranging from 34 to 111 °C. This study investigates the chemical recycling and the solvent resistance of these vitrimer-like materials that have a high bio-based carbon content, from 58 to 79%, with potential application in coating or composite materials in the automotive sector.

Impacts of phosphorous-linked epoxidized vegetable oil on mechanical behaviors and flammability properties of silica reinforced epoxy composite

Although widely used in industrial applications, epoxy resins generally display low toughness and high flammability. The use of phosphorus compounds can improve flame-retardant capabilities along with reducing mechanical properties. Herein, the novel flame-retardant additive of phosphorous-linked epoxidized vegetable oil (P-L-EVO) was fabricated from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and epoxidized vegetable oil through a ring opening reaction before applying it as additive for an epoxy/silica system. The silica was extracted from a rice husk using a combined approach of acid treatment and thermal treatment. Successful grafting and extraction reactions were confirmed using Fourier transform infrared analysis (FTIR) and nuclear magnetic resonace (NMR). The epoxy resin-based samples were cured with diethylenetriamine (DETA) hardener at ambient conditions. The influences of additives on the mechanical properties and flame-retardant capabilities were examined via tensile strength, impact strength, critical stress intensity (KIC), a cone calorimeter, the limited oxygen index (LOI), and the UL 94 vertical test. The epoxy sample with 20 wt.% silica and 10 wt.% of P-L-EVO (S20.10) reached the LOI value of 35.89 % and a V0 rating of UL94. Moreover, this combination improved the impact strength, tensile strength, and KIC by up to 90.16 %, 20.28 %, and 73.84 %, respectively in comparison with pristine epoxy sample (S00.00). The formation of a non-thermal decomposition char layer along with a release of flame-retardant radicals was considered the novel flame-retardant mechanism.

The Application of Quantitative Structure–Property Relationship Modeling and Exploratory Analysis to Screen Catalysts for the Synthesis of Oleochemical Carbonates from CO2 and Bio‐Based Epoxides

AbstractScreening catalysts for the synthesis of cyclic carbonates from CO2 and epoxides presents a challenge for the research community. Thus, we propose the application of quantitative structure–property relationships (QSPR) modeling and exploratory analysis to assist in the selection of catalysts to produce oleochemical carbonates. QSPR modeling was developed by applying 2D‐descriptors to evaluate the relationship between the molecular structure of organocatalysts and their activity in the production of bio‐based organic carbonates. From the virtual screening, 122 potential catalysts were selected, their catalytic activities were estimated, and the best molecular targets highlighted. Already from the data mining and exploratory analysis, the catalysts' key structural features (e.g. organic structure, molecular arrangement, carbon chain size, and substituent type) were identified. Thus, it was possible to evaluate the similarity between the catalysts and to relate the 2D‐descriptors to their activity. Then, based on QSPR modeling results, cetyltrimethylammonium bromide (CTAB) was proposed as a new catalyst to produce oleochemical carbonates. From the CTAB application, conversions greater than 98% of epoxide were observed in the cycloaddition of CO2 to epoxidized vegetable oil (rice bran, canola, and soybean). Thus, it was concluded that QSPR modeling and exploratory analysis show potential for screening catalysts for oleochemical carbonate synthesis.

Synthesis of Bio‐Based Cyclic Carbonates Using a Bio‐Based Hydrogen Bond Donor: Application of Ascorbic Acid to the Cycloaddition of CO2 to Oleochemicals

AbstractOleochemicals such as functionalized fatty acid esters and vegetable oils are classes of renewably sourced compounds that are increasingly attracting attention in sustainable chemistry as replacement for fossil‐fuel based chemicals. The possibility of coupling CO2 with epoxidized fatty acids esters (EFAEs) and epoxidized vegetable oils (EVOs) to afford compounds that are attractive as additives or chemical intermediates in the synthesis of non‐isocyanate polyhydroxyurethanes (NIPU) can conjugate highly sought‐after CO2 valorization with the exploitation of bio‐based substrates. In this context, there have been very few attempts to employ organocatalytic hydrogen bond donors (HBDs) in the cycloaddition reaction of CO2 to EFAEs and EVOs and no studies focusing on bio‐based and readily available HBDs. In this work we show that ascorbic acid is an efficient HBD for the cycloaddition of CO2 to EFAEs and EVOs under mild reaction conditions of temperature (80–100 °C) and pressure (5–10 bar) that could be applied to several kinds of substrates (monounsaturated EFAEs, polyunsaturated EFAEs and EVOs). In all cases, the formed by‐products (ketones, allylic alcohols, cyclic ethers etc.) were identified and the reaction conditions were tuned in order to obtain the target carbonates, generally, in high yields and selectivity.

Chemical Reactivity and the Influence of Initiators on the Epoxidized Vegetable Oil/Dicarboxylic Acid System

In a sustainable development context, epoxidized vegetable oils (EVO) have unlimited and promising future prospects as renewable and environmentally friendly feedstock. The only drawback to their u...

Sustainable access to fully biobased epoxidized vegetable oil thermoset materials prepared by thermal or UV-cationic processes.

Beyond the need to find a non-toxic alternative to DiGlycidyl Ether of Bisphenol-A (DGEBA), the serious subject of non-epichlorohydrin epoxy resins production remains a crucial challenge that must be solved for the next epoxy resin generations. In this context, this study focuses on the valorization of vegetable oils (VOs) into thermoset materials by using (i) epoxidation of the VOs through the “double bonds to epoxy” synthetic route and (ii) synthesis of crosslinked homopolymers by UV or hardener-free thermal curing processes. A thorough identification, selection and physico-chemical characterization of non-edible or non-valuated natural vegetable oils were performed. Selected VOs, characterized by a large range of double bond contents, were then chemically modified into epoxides thanks to an optimized, robust and sustainable method based on the use of acetic acid, hydrogen peroxide and Amberlite® IR-120 at 55 °C in toluene or cyclopentyl methyl ether (CMPE) as a non-hazardous and green alternative solvent. The developed environmentally friendly epoxidation process allows reaching almost complete double bond conversion with an epoxy selectivity above 94% for the 12 studied VOs. Finally, obtained epoxidized vegetable oils (EVOs), characterized by an epoxy index from 2.77 to 6.77 meq. g−1 were cured using either UV or hardener-free thermal curing. Both methods enable the synthesis of 100% biobased EVO thermoset materials whose thermomechanical performances were proved to linearly increase with the EVOs' epoxy content. This paper highlights that tunable thermomechanical performances (Tα from −19 to 50 °C and Tg from −34 to 36 °C) of EVO based thermoset materials can be reached by well selecting the starting VO raw materials.

The epoxidation of linseed oil with in situ formed peracetic acid: A model with included influence of the oil fatty acid composition

The epoxidation of vegetable oils with percarboxylic acids yields commercially applicable green products/precursors for the polymer industry. A reliable model of this reaction system could help to improve the quality of the produced epoxidized vegetable oils. A biphasic model, pseudohomogenous with respect to the catalyst, was proposed for the vegetable oil epoxidation with peracetic acid formed in situ in the presence of an ion exchange resin. The model takes into consideration the influence of the oil fatty acid composition, as an important property of this renewable raw material, on the kinetics of the process. Non-edible linseed oil was chosen for the study since it contains significant amounts of different unsaturated fatty acids, i.e., linolenic (54.8%), linoleic (16.0%) and oleic (19.8%) acids, in its triglycerides. The effects of temperature (333–358 K), molar ratio of linseed oil double bond:hydrogen peroxide (1:1.1–1:1.5), catalyst amount (10–20 wt%) and reaction time (1–17 h) on the relative epoxy yield and the process selectivity were investigated. The proposed model explained the experimental data concerning changes in double bond and epoxy group amounts during the linseed oil epoxidation with a standard deviation of less than 0.024. The partition coefficient for acetic acid between the liquid phases of the reaction system, as the thermodynamic constant in the model, was separately determined for the linseed oil-epoxidized linseed oil-acetic acid-hydrogen peroxide-water system. Its values ranged from 0.0705–0.3159. The kinetic study showed that one double bond per linolenic acid chain has significantly higher reactivity towards the epoxidation reaction compared to other double bonds in the linseed oil triglyceride. The reactivity difference between these double bonds increased from 6.5 to 41 times with the temperature rise from 333 to 358 K.

Catalytic developments in the epoxidation of vegetable oils and the analysis methods of epoxidized products.

Functionalization of vegetable oils (VOs) including edible, non-edible, and waste cooking oil (WCOs) to epoxides (EVOs) is receiving great attention by many researchers from academia and industry because they are renewable, versatile, sustainable, non-toxic, and eco-friendly, and they can partially or totally replace harmful phthalate plasticizers. The epoxidation of VOs on an industrial scale has already been developed by the homogeneous catalytic system using peracids. Due to the drawbacks of this method, other systems including acidic ion exchange resins, polyoxometalates, and enzymes are becoming alternative catalysts for the epoxidation reaction. We have reviewed all these catalytic systems including their benefits and drawbacks, reaction mechanisms, intensification of each system in different ways as well as the physicochemical properties of VOs and EVOs and new findings in recent years. Finally, the current methods including titrimetric methods as well as ATR-FTIR and 1H NMR for determination of conversion, epoxidation, and selectivity of epoxidized vegetable oils (EVOs) are also briefly described.

High toughness poly(lactic acid) (PLA) formulations obtained by ternary blends with poly(3-hydroxybutyrate) (PHB) and flexible polyesters from succinic acid

This work reports the development of poly(lactic acid) (PLA) formulations with improved toughness by ternary blends with poly(3-hydroxybutyrate) (PHB) and two different flexible polyesters derived from succinic acid, namely poly(butylene succinate) (PBS) and a copolymer, poly(butylene succinate-co-adipate) (PBSA). The main aim of this work is to increase the low intrinsic toughness of PLA without compromising the thermal properties by manufacturing ternary blends using epoxidized vegetable oils as compatibilizer agents. The ternary blends were manufactured by reactive extrusion in a co-rotating extruder and were subjected to mechanical, thermal, thermos-mechanical and morphology characterization. The obtained results confirm that these two succinic acid-derived polymers, i.e., PBS and PBSA, positively contribute to increase ductile properties in ternary blends with PLA and PHB with a subsequent improvement on impact toughness. In addition, both epoxidized vegetable oils, ELO and ESBO, are responsible for somewhat compatibilization between all three polyesters in blends which gives improved ductile properties with regard to uncompatibilized ternary blends. In addition, the temperature range in which these materials can be used is broader than ternary blends with other flexible polyester such as poly(e-caprolactone), as both PBS and PBSA melt at about 100 °C. These PLA-based materials with improved impact properties offer interesting applications in the packaging industry.

Green epoxy synthesized from Perilla frutescens: A study on epoxidation and oxirane cleavage kinetics of high-linolenic oil

Despite the growing interest in epoxidized vegetable oils (EVOs) as sustainable alternatives to petroleum-based epoxies, their high epoxy equivalent weight (EEW) (>250 g/eq) hinders use in high-strength applications. This study reports the synthesis of a sustainable EVO that possesses EEW of ∼164 g/eq – comparable to that of diglycidyl ether of bisphenol-A (DGEBA). Non-edible perilla oil, extracted from the non-edible seeds of Perilla frutescens, was used to synthesize sustainable green epoxy via Prilezhaev epoxidation reaction at 40, 50 and 60 °C for 8 h. Perilla oil was chosen due to its higher number of chemically modifiable groups (>90%), i.e. ∼62–65 wt. % linolenic acid (C18:3), ∼13–15 wt. % linoleic acid (C18:2) and ∼12–15 wt. % oleic acid (C18:1) moieties. Rates of epoxidation and side reactions were estimated by experimentally determining iodine, epoxy and α-glycol value of epoxidized perilla oil (EPeO) extracted at regular time intervals during synthesis. Kinetics of post-oxirane cleavage was studied at aforementioned reaction temperatures and times by reacting EPeO with formic acid in weight ratio of 1:3. Reaction kinetics studies for both epoxidation and ring opening reactions (pseudo) showed reaction rate constants in the order of 10−6 L mol−1 s−1 (for both reactions) and activation energies of 20.10 kJ/mol (epoxidation) and 43.11 kJ/mol (ring opening) respectively. Thermodynamic parameters – such as activation enthalpy, activation entropy, and Gibbs’ free energy of activation – were calculated for both epoxidation and oxirane ring cleavage reactions. All the thermodynamic parameters were observed to be lower for epoxidation reaction compared to post-oxirane cleavage reaction. Enthalpy of activation was found to be ∼18 kJ/mol for epoxidation reaction while it was ∼56 kJ/mol for post-oxirane cleavage reaction.

Sustainable synthesis of epoxidized waste cooking oil and its application as a plasticizer for polyvinyl chloride films

For the past decade, environmentally friendly features have been one of the most desired characteristics of most of the arising technologies. The search for materials from renewable sources and the development of novel non-hazardous processes for their production is currently of the utmost relevance. However, significant improvements on the current technologies towards greener less energy-demanding processes are as important as the search for new ones, and sometimes improvements are more easily achievable and more readily applicable. In this work, the feasibility of using waste cooking oil as a feedstock for the production of epoxidized vegetable oil resins in a process devoid of catalyst has been demonstrated. The epoxidation process was carried out using citric acid as the only acidic component, generating no solid residues and a liquid residue less toxic than the one from the conventional processes. The produced epoxidized waste vegetable oil was successfully applied as a primary plasticizer in poly(vinyl chloride) (PVC) films. The produced films showed mechanical and thermal properties matching those of commercial stretch PVC films.

Preparation and characterization of polymeric dispersants based on vegetable oils for printing ink application

In this work, a novel vegetable oil-based polymers were prepared by epoxidation of soybean oil (SBO) and castor oil (CO) followed by ring opening reaction of epoxidized oil with polyether amine and poly propylene glycol. The prepared polymers were characterized by FTIR and GPC. The properties of vegetable oils and epoxidized vegetable oil (EVO) were studied. The prepared polymers were employed as novel polymeric dispersants for pigment dispersion in solvent based printing ink application. The mechanical and optical properties of prepared ink were studied. The net technical properties of the new ink formulations are relatively comparable to the prepared printing ink from standard polymeric dispersant. The polymeric dispersant 2 (PD2) and polymeric dispersant 4 (PD4) gave the best optical and mechanical properties among the prepared polymers.

Synthesis and characterization of alkyd resins based on Camelina sativa oil, glycerol and selected epoxidized vegetable oils as functional modifiers

Abstract Novel alkyd resins based on the Camelina sativa oil as a new renewable raw material and glycerol as a polyol component were synthesized. Selected epoxidized vegetable oils (linseed oil and camelina oil) as new functional modifiers were used in the alcoholysis reaction with purified camelina oil. The influence of the added epoxidized linseed oil and epoxidized camelina oil on the course of alkyd resin synthesis and the properties of the final products were investigated. The glycerol-based alkyd resins with improved properties were produced.

Iron-Based Binary Catalytic System for the Valorization of CO2 into Biobased Cyclic Carbonates

The atom economic conversion of epoxidized vegetable oils and fatty acid derivatives with CO2 into cyclic carbonates permits the synthesis of novel oleo compounds from renewable resources as well as the valorization of CO2 as a C1-building block. Organic phosphorus salts proved to be selective catalysts for this reaction. In a widespread screening 11 inexpensive and nontoxic iron salts were evaluated as cocatalysts to enhance the reaction rate. In the presence of 0.25 mol % iron chloride the selectivity and conversion were significantly improved. The reaction parameters were optimized under solvent-free conditions, and the scope and limitation were evaluated for 9 epoxidized fatty acid esters and 4 epoxidized vegetable oils. The biobased carbonates were isolated in excellent yields up to 95% and can be considered to be based on 100% CO2 in respect to carbon. This binary catalyst system features high efficiency and plain simplicity while valorizing CO2 into cyclic carbonates based on renewable feedstocks.