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With the increasing demand for eco-friendly epoxides derived from vegetable oils, recent efforts have focused on developing methods for the epoxidation of sunflower oil. Sunflower oil, in particular, has emerged as a promising candidate for epoxidation due to its high content of unsaturated fatty acids, which provide abundant double bonds suitable for epoxide formation. In this study, epoxidized sunflower oil was produced using in situ formed peracid with a hybrid oxygen carrier combining formic acid and acetic acid. The optimal epoxidation reaction parameters were determined as follows: (1) a reaction temperature of 75 °C, (2) a catalyst loading of 0.9 g of hybrid oxygen carrier, (3) a stirring speed of 450 rpm, and (4) a hydrogen peroxide to sunflower oil molar ratio of 1.5. This research contributes to transforming sunflower oil into a value-added product, thereby reducing reliance on petroleum-based resources. [ABSTRACT FROM AUTHOR]

Recently, the trend of using renewable sources has great attention in the production of polyol chemicals via the epoxidation method. Palm-based polyols produced from the epoxidation and hydroxylation methods usually have low hydroxyl values (below 200 mg KOH/g). This study aimed to synthesize the hydroxylase polyols with a higher hydroxyl value from the renewable source palm oil. The epoxidized palm oleic acid was synthesized using the in situ performic acid, which is obtained from the reaction of formic acid and hydrogen peroxide. The Taguchi method was executed to optimize the epoxidation process for the maximum production of epoxidized oleic acid. Then, optimized epoxidized palm oleic acid was hydroxylated to produce polyols. In addition, the effect of process parameters on the polyol yields was also studied. At the optimum process parameters, the response of relative conversion to oxirane (RCO) with the determination of oxirane oxygen content (OOC) was found at the maximum value of 82%. According to the results, the maximum hydroxyl value produced was 339 mg KOH/g. A kinetic study revealed that the oxirane cleavage by methanol is a second-order reaction whereas the formation of epoxidized palm oleic acid is a first-order reaction. [ABSTRACT FROM AUTHOR]

Manganese catalysts that activate hydrogen peroxide have seen increased use in organic transformations, such as olefin epoxidation and alkane C−H bond oxidation. Proposed mechanisms for these catalysts involve the formation and activation of MnIII‐hydroperoxo intermediates. Examples of well‐defined MnIII‐hydroperoxo complexes are rare, and the properties of these species are often inferred from MnIII‐alkylperoxo analogues. In this study, we show that the reaction of the MnIII‐hydroxo complex [MnIII(OH)(6Medpaq)]+ (1) with hydrogen peroxide and acid results in the formation of a dark‐green MnIII‐hydroperoxo species [MnIII(OOH)(6Medpaq)]+ (2). The formulation of 2 is based on electronic absorption, 1H NMR, IR, and ESI‐MS data. The thermal decay of 2 follows a first order process, and variable‐temperature kinetic studies of the decay of 2 yielded activation parameters that could be compared with those of a MnIII‐alkylperoxo analogue. Complex 2 reacts with the hydrogen‐atom donor TEMPOH two‐fold faster than the MnIII‐hydroxo complex 1. Complex 2 also oxidizes PPh3, and this MnIII‐hydroperoxo species is 600‐fold more reactive with this substrate than its MnIII‐alkylperoxo analogue [MnIII(OOtBu)(6Medpaq)]+. DFT and time‐dependent (TD) DFT computations are used to compare the electronic structure of 2 with similar MnIII‐hydroperoxo and MnIII‐alkylperoxo complexes. [ABSTRACT FROM AUTHOR]

The efficient conversion of long‐chain linear α‐olefins (LAOs) into industrially useful epoxides is of pivotal importance. Mukaiyama epoxidation based on the use of molecular oxygen as the sole oxidant and aldehyde as the cosubstrate offers a promising route for LAOs epoxidation. However, challenges associated with epoxide forming selectivity and aldehyde coupling efficiency have long impeded the adoption of Mukaiyama epoxidation in large‐scale applications. Herein, we show that confinement of key intermediates involved in the parallel epoxidation pathways within a Beta zeolite unlocks a selectivity of greater than 95 % towards the epoxides at the expense of minimal consumption of only 1.5 equivalents of the aldehyde, achieving an efficiency better than the state‐of‐the‐art homogeneous and heterogeneous catalysts. Moreover, the incorporation of Sn sites into the Beta zeolite framework further facilitates the adsorption activation process of the aldehyde cosubstrate, thereby increasing the concentration of acylperoxy radicals and accelerating the kinetic process of the epoxidation step. Consequently, this work not only provides an efficient and green epoxidation route over zeolite catalysts with easily available O2 as the oxidant, but also systematically reveals the fundamental understanding of the zeolite confinement effects on steering the reaction pathway, which benefits the further development of valorization of LAOs. [ABSTRACT FROM AUTHOR]

Unspecific peroxygenases (UPOs) catalyze the selective oxygenation of organic substrates using only hydrogen peroxide as the external oxidant. The PaDa−I variant of the UPO from Agrocybe aegerita catalyses the oxidation of Z‐ and E‐allylic alcohols with complementary selectivity, giving epoxide and carboxylic acid/aldehyde products respectively. Both reactions can be performed on preparative scale with isolated yields up to 80 %, and the epoxidations proceed with excellent enantioselectivity (>99 % ee). The divergent reactions can also be used to transform E/Z mixtures of allylic alcohols, enabling both product series to be isolated from a single reaction. The utility of the epoxidation method is exemplified in the total synthesis of both enantiomers of the insect pheromone disparlure, including a highly enantioselective gram‐scale transformation. These reactions provide further evidence for the potential of UPOs as catalysts for the scalable preparation of important oxygenated intermediates. [ABSTRACT FROM AUTHOR]

We report on the synthesis of amphiphobic fluorinated surface‐active ionic liquid (FSAIL) epoxidation catalysts, which show reversible temperature‐controlled solubility in water. The solubility of FSAILs containing the catalytically active perrhenate‐ and tungstate anions was studied in both the aqueous and the substrate phase, showing a significant solubility decrease in both media compared to their non‐fluorinated congeners. It was shown that both the epoxide product and the catalyst additive phenylphosphonic acid (PPA) are efficient in transferring the FSAIL catalyst into the organic phase, rendering the reaction homogeneous. The FSAILs were used as catalysts for the epoxidation of olefins using aqueous H2O2 as oxidant, showing an exceptionally high catalytic activity at mild conditions. Catalyst recycling was demonstrated over ten consecutive runs by phase separation and subsequent product distillation. [ABSTRACT FROM AUTHOR]

Numerous efforts focus on renewable epoxy resin development, with lignin emerging as a viable green alternative to fossil‐derived resources. Being Earth's second‐most abundant organic molecule, lignin, rich in phenolic groups, shows promise as a substitute for bisphenol A in diglycidyl ether of bisphenol A (DGEBA) production. This work successfully modifies Kraft lignin (KL) via one‐step epoxidation (KLE) and phenolation prior to epoxidation (KLPE), significantly increasing oxirane ring content. Characterization via FTIR and 1H NMR spectroscopy validates the modifications, yielding epoxy equivalent weights of 862.1 and 214.6 g mol−1 for KLE and KLPE, respectively. Incorporating 20 wt% KLE into adhesive maintains tensile and lap shear strength compared to 100 wt% DGEBA adhesives, with an increase in elastic modulus, indicating its potential as a sustainable resin substitute. However, phenolation prior to epoxidation slightly reduces mechanical properties despite higher oxirane ring concentration. These results shed some light on the impact of both modification protocols on the mechanical properties of epoxy adhesives, supporting the development and properties optimization of sustainable epoxy adhesives. [ABSTRACT FROM AUTHOR]

The quest for polymers that would be at the same time bio‐based and degradable after usage, in addition to offering chemical post‐modification options, remains a daunting challenge in contemporary polymer science. Despite advances in polymer chemistry, attempts at controlling the chain‐growth polymerization of muconate esters remain unexplored. Here we show that dialkyl muconates can be rapidly polymerized by organocatalyzed group transfer polymerization (O‐GTP). O‐GTP is conducted to completion at room temperature in toluene within a few minutes, using 1‐ethoxy‐1‐(trimethylsiloxy)‐1,3‐butadiene (ETSB) as initiator and 1‐tert‐butyl‐4,4,4‐tris(dimethylamino)‐2,2‐bis[tris(dimethylamino)‐phosphoranylidenamino]‐2λ ${\lambda }$ 5,4λ ${\lambda }$ 5 catenadi(phosphazene) (P4‐t‐Bu) as catalyst. Chain extension experiments and synthesis of all muconate‐type block copolymers can also be achieved. Furthermore, polymuconates are amenable to facile post‐polymerization modification reactions. This is showcased through the hydrolysis of the ester side chains leading to well‐defined poly(muconic acid), and by epoxidation of the C=C double bonds of the main chain. Last but not least, these internal alkene groups can be selectively cleaved by ozonolysis, demonstrating the upcyclability of polymuconates under oxidative conditions. This work demonstrates that polymuconates constitute a unique platform of bio‐based polymers, easily modifiable in addition to being chemically degradable under user friendly experimental conditions. [ABSTRACT FROM AUTHOR]

A new microporous supramolecular-framework Ru(II)–porphyrin catalyst containing non-covalent interactions between pyrenylphenyl moieties at the meso-position of the porphyrin ring is synthesised and structurally characterised. This recyclable catalyst expedites styrene epoxidation more efficiently than homogeneous Ru–porphyrin catalytic systems. [ABSTRACT FROM AUTHOR]

Single‐site molybdenum dioxo catalysts, fullerenol/MoO2, are prepared via grafting precursor (DME)MoO2Cl2 onto a highly polyhydroxylated fullerene (ful) and an isomerically‐pure and well‐defined fullerene (ful*). These catalyst structures are characterized by ICP‐OES, XPS, XANES, EXAFS, DRIFT, Raman, and NMR spectroscopy, and DFT. Mo 3d5/2 XPS and Mo K‐edge XANES assign the oxidation state as Mo(VI). Mo EXAFS data fitting reveals two Mo=O double and two Mo−O single bonds at distances of 1.7 and 1.9 Å, respectively, while an Mo=O stretchingl mode is observed at ~950 cm−1 by DRIFT and Raman spectroscopy. These data align well with DFT computational results, supporting the proposed catalyst structure as Fullerene(‐μ‐O‐)2M(=O)2. Additionally, DFT provides insight into the energetically favorable grafting sites for an isomerically pure fullerenol. The scope of fullerenol/MoO2 mediated alkene epoxidation includes abiotic alkenes, natural occurring terpenes, and conjugated olefins. For cyclooctene the rate law is first‐order in [Mo], near first order in [olefin] and zero‐order in [t‐butyl hydroperoxide]. A plausible reaction mechanism involves peroxide addition first and then cyclooctene addition directly across the peroxo bond forming the epoxide product, consistent with DFT computation. Overall, fullerenol/MoO2 shows promise as a sustainable and structurally well‐defined system with versatile catalytic activity and good epoxidation recyclability. [ABSTRACT FROM AUTHOR]

The delineation of the complex biosynthesis of the potent antibiotic mupirocin, which consists of a mixture of pseudomonic acids (PAs) isolated from Pseudomonas fluorescens NCIMB 10586, presents significant challenges, and the timing and mechanisms of several key transformations remain elusive. Particularly intriguing are the steps that process the linear backbone from the initial polyketide assembly phase to generate the first cyclic intermediate PA‐B. These include epoxidation as well as incorporation of the tetrahydropyran (THP) ring and fatty acid side chain required for biological activity. Herein, we show that the mini‐module MmpE performs a rare online (ACP‐substrate) epoxidation and is integrated ('in‐cis') into the polyketide synthase via a docking domain. A linear polyketide fragment with six asymmetric centres was synthesised using a convergent approach and used to demonstrate substrate flux via an atypical KS0 and a previously unannotated ACP (MmpE_ACP). MmpE_ACP‐bound synthetic substrates were critical in demonstrating successful epoxidation in vitro by the purified MmpE oxidoreductase domain. Alongside feeding studies, these results confirm the timing as well as chain length dependence of this selective epoxidation. These mechanistic studies pinpoint the location and nature of the polyketide substrate prior to the key formation of the THP ring and esterification that generate PA‐B. [ABSTRACT FROM AUTHOR]

To synthesize high-quality TS-1 zeolites with enhanced catalytic performance for 1-hexene epoxidation is highly attractive for meeting the increased need for sustainable chemistry. Herein, we report that a series of framework Ti-enriched TS-1 zeolites with high crystallinity can be effectively synthesized by the hydrothermal crystallization of a composite precursor composed of diol-based polymer (containing titanium and silicon) and tetrapropylammonium bromide (TPABr). The pre-addition of a certain amount of TPABr into the polymer-based precursor plays a very positive role in maintaining the high crystallinity and framework Ti incorporation rate of TS-1 zeolites under the premise that a relatively low concentration of tetrapropylammonium hydroxide (TPAOH) template is adopted in the following hydrothermal crystallization process. The condition-optimized TS-1 zeolite with a smaller particle size (300–500 nm) shows excellent catalytic activity, selectivity, and recyclability for the epoxidation of 1-hexene with H2O2 as an oxidant, which can achieve a 75.4% conversion of 1-hexene and a 99% selectivity of epoxide at a reaction temperature of 60 °C, which is much better than the TS-1 zeolites reported in the previous literature. The relatively small particle size of the resultant TS-1 crystals may enhance the accessibility of the catalytically active framework Ti species to reagents, and the absence of non-framework Ti species, like anatase TiO2, and low polymerized six-coordinated Ti species could effectively inhibit the ineffective decomposition of H2O2 and the occurrence of side reactions, leading to an improvement in the catalytic efficiency for the epoxidation of 1-hexente with H2O2. [ABSTRACT FROM AUTHOR]

An open‐chain iron pyridine‐NHC framework is expanded utilizing a benzimidazole moiety to deepen the understanding of the impact of electronic variations on iron NHC epoxidation catalysts, especially regarding the stability. The thereby newly obtained iron(II) NHC complex is characterized and employed in olefin epoxidation. It is remarkably temperature tolerant and achieves a TOF of ca. 10 000 h−1 and TON of ca. 700 at 60 °C in the presence of the Lewis acid Sc(OTf)3, displaying equal stability, but lower activity than the unmodified iron pyridine‐NHC (pre‐)catalyst. In addition, a synthetic approach towards another ligand containing 2‐imidazoline units is described but formylation as well as hydrolysis hamper its successful synthesis. [ABSTRACT FROM AUTHOR]

There is a continuing search for materials having desirable fragrance properties. Such materials are sought either to replace costly natural materials or to provide new fragrances or perfume types, which have not heretofore been available. Hence, the objective of this paper is the synthesis and olfactory characterization of new fragrant materials through chemical modification of methyleugenol (ME) molecular framework by introducing Ester functional groups using appropriate standard procedures. ME is a common phenylpropanoid found in many plant species, particularly in spices and medicinal plants. It is used as a flavouring agent in food and as a fragrance in cosmetics. In this research, methyleugenol was modified to obtain esters. The transformations involve the opening of 2-(4-ethyl-3-methoxybenzyl) oxirane (epoxide ring) to yield 3-(3,4-dimethoxyphenyl)propane-1,2-diol (Dihydroxy). 1-(3,4-dimethoxyphenyl)-3-hydroxypropan-2-yl acetate (53.33% yield) derivatives, was synthesized from the Dihydroxy. The results showed that the odour characteristic of 3-(3,4-dimethoxyphenyl)propane-1,2-diol [floral, pungent, Caramel and sweet] compounds, is clearly different from the odours of the 1-(3,4-dimethoxyphenyl)-3-hydroxypropan-2-yl acetate [fresh, pungent, lime-like, sweet]. Our findings show that double bond substitution and functional alterations to methyl eugenol modify the perceived odour of methyl eugenol derivatives. Thus, overall structural alteration increased odour potency. [ABSTRACT FROM AUTHOR]

The development of green route for preparing propylene oxide (PO) with molecular oxygen is of significance both in academic and industrial. In this work, propylene epoxidation coupled with furfural oxidation catalyzed by platinum meso-tetraphenylporphyrin (Pt (II)TPP) has been developed. Propylene conversion and PO selectivity reached up to 56% and 83%, respectively. Meanwhile, furfural was almost completely converted to furoic acid. Based on operando characterizations and electron paramagnetic resonance (EPR) tests, a mechanism involved high-valent Pt species was proposed. This work is expected to provide a potential application prospects for producing PO and furoic acid simultaneously in chemical industry. [ABSTRACT FROM AUTHOR]

Irumamycin (Iru) is a complex polyketide with pronounced antifungal activity produced by a type I polyketide (PKS) synthase. Iru features a unique hemiketal ring and an epoxide group, making its biosynthesis and the structural diversity of related compounds particularly intriguing. In this study, we performed a detailed analysis of the iru biosynthetic gene cluster (BGC) to uncover the mechanisms underlying Iru formation. We examined the iru PKS, including the domain architecture of individual modules and the overall spatial structure of the PKS, and uncovered discrepancies in substrate specificity and iterative chain elongation. Two potential pathways for the formation of the hemiketal ring, involving either an olefin shift or electrocyclization, were proposed and assessed using 18O-labeling experiments and reaction activation energy calculations. Based on our findings, the hemiketal ring is likely formed by PKS-assisted double bond migration and TE domain-mediated cyclization. Furthermore, putative tailoring enzymes mediating epoxide formation specific to Iru were identified. The revealed Iru biosynthetic machinery provides insight into the complex enzymatic processes involved in Iru production, including macrocycle sculpting and decoration. These mechanistic details open new avenues for a targeted architecture of novel macrolide analogs through synthetic biology and biosynthetic engineering. [ABSTRACT FROM AUTHOR]

Zr‐monosubstituted polyoxometalates (Zr‐POMs) of the Keggin (Bu4N)8[{PW11O39Zr(μ‐OH)}2] (Zr‐K), Lindqvist (Bu4N)6[{W5O18Zr(μ‐OH)}2] (Zr‐L), and Wells‐Dawson (Bu4N)11H3[{P2W17O61Zr(μ‐OH)}2] (Zr‐WD) structures are capable of heterolytic activation of the environmentally benign oxidant tert‐butyl hydroperoxide (TBHP) and catalyze epoxidation of alkenes and oxidation of alcohols to carbonyl compounds. Catalytic activity of corresponding Ti‐POMs is much lower. Among Zr‐POMs, Zr‐K revealed higher epoxide yields. All Zr‐POMs do not catalyze unproductive TBHP degradation, and epoxide yields with both aqueous and anhydrous TBHP are generally higher than with aqueous H2O2. Regioselectivity of the Zr‐K‐catalyzed limonene epoxidation with TBHP is different from that with H2O2: the more substituted and nucleophilic double bond is preferably epoxidized, pointing to an electrophilic oxygen transfer mechanism. The oxidation rates are first order in catalyst (Zr‐K) and substrate (cyclooctene or cyclohexanol) and show a saturation behavior with increasing concentration of TBHP. Studies by HR‐ESI‐MS, ATR‐FT‐IR, and 31P NMR spectroscopic techniques implicated the formation of zirconium alkylperoxo species upon interaction of Zr‐POMs with TBHP. HR‐ESI‐MS revealed the existence of monomeric and dimeric alkylperoxo complexes, [{PW11O39Zr}((CH3)3COO)]4− and [{PW11O39Zr((CH3)3COO)}2]8−, with predomination of the former, which is most likely the active species responsible for the selective oxidations. [ABSTRACT FROM AUTHOR]

The direct epoxidation of propylene with molecular oxygen represents a desired route for propylene oxide (PO) production with 100% theoretical atomic economy. However, this aerobic epoxidation reaction suffers from the apparent trade-off between propylene conversion and PO selectivity, and remains a key challenge in catalysis. We report that Ti-Beta zeolites containing isolated framework Ti species can efficiently catalyze the aerobic epoxidation of propylene. Stable propylene conversion of 25% and PO selectivity of up to 90% are achieved at the same time, matching the levels of industrial ethylene aerobic epoxidation processes. H-terminated pentacoordinated Ti species in Beta zeolite frameworks are identified as the preferred active sites for propylene aerobic epoxidation and the reaction is initiated by the participation of lattice oxygen in Ti-OH. These results are expected to spark new technology for the industrial production of PO toward more sustainable chemistry and chemical engineering. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the effects of different types of catalysts – sulphuric acid titanium dioxide, and Amberlite – and to investigate the effect of catalyst loading (0.1 g, 0.5 g, 1.0 g) on the relative conversion to oxirane (RCO %). This study examines the influence of these different catalyst types and their loadings on the epoxidation of palm oil to identify the optimum conditions for the process. The epoxidised palm oil was analysed using RCO % and Fourier transform infrared spectroscopy (FTIR). The results showed that 0.5 g sulphuric acid as a catalyst with a loading of 0.5 g achieved the highest RCO % at 76.16 %. FTIR spectra revealed the presence of an epoxy group at 833.10 cm-1. In conclusion, using 0.5 g of sulphuric acid as the catalyst provides the optimum conditions for the epoxidation process. [ABSTRACT FROM AUTHOR]

In this study, waste cooking oil‐based palm oil (WCO‐PO) was chosen as feedstock for epoxidation reaction. The epoxidation process of WCO‐PO was carried out using in situ generated performic acid or known as Prileschajew reaction. Based on the Taguchi method of optimization and analysis of variance, a series of experiments were conducted around the optimum conditions or parameters. The findings revealed that the optimal reaction conditions for producing epoxidized waste cooking oil with the highest oxirane content were a hydrogen peroxide molar ratio of 2.0, a temperature of 55°C, formic acid molar ratio of 2.0, and catalyst loading of 0.5% at a constant stirrer speed of 300 rpm and 0.5% catalyst. By employing these optimal conditions, the maximum relative conversion of waste cooking oil to oxirane was achieved at 70.6%. Besides, the rate constant and activation energy for epoxidation of WCO‐PO at optimum condition were 0.0221 min−1 and 50.55 kJ mol−1, respectively. Overall, epoxidized WCO‐PO was successfully produced by using optimum process parameters of epoxidation. [ABSTRACT FROM AUTHOR]

With the increasing focus on sustainable development, the exploration of renewable and environmentally friendly resources for product synthesis has become paramount. This study aims to investigate the production of dihydroxystearic acid through the in situ hydrolysis of epoxidized oleic acid. Epoxidation of oleic acid was achieved through the utilization of in situ generated performic acid, resulting in the production of epoxidized oleic acid. The synthesis of performic acid involved the combination of formic acid as an oxygen carrier and hydrogen peroxide as an oxygen donor. A maximum epoxide yield of 65% was attained at an optimum reaction time of 30 min. Hydrochloric acid was found to be the most efficient catalyst. A kinetics study was also done using the genetic algorithm to find the reaction rate of dihydroxystearic acid production. The difference between simulation and experimental results was less than 0.1%, which is insignificant. The findings highlight the potential of utilizing renewable resources for the synthesis of high-value compounds, promoting a greener and more sustainable future. [ABSTRACT FROM AUTHOR]

In recent years, there has been a focused effort to reduce the harmful effects of synthetic and mineral-based lubricants by emphasizing the use of biodegradable-based lubricants. These lubricants play a crucial role in minimizing friction, ensuring smooth operation of machines, and reducing the likelihood of frequent failures. With petroleum-based reserves depleting worldwide, prices are rising, and environmental damage is increasing. However, biolubricants derived from nonedible vegetable oils offer environmental benefits as they are nontoxic, emit minimal greenhouse gases, and are biodegradable. In this study, biolubricants are synthesized from jatropha and jojoba oil using sulphuric acid (H2SO4) and hydrochloric acid (HCl) as catalysts through the transesterification and epoxidation processes. The optimization of influencing parameters is achieved using Taguchi's orthogonal array, a statistical methodology. By employing design of experiments (DOE), the number of experimental trials is minimized while providing comprehensive details on the impact of control factors such as molar ratio, catalyst concentrations, and temperature. The results obtained from DOE reveal that the best optimized yield for jatropha biolubricant with H2SO4 and HCl catalysts is achieved with a molar ratio of 0.5:1.5, a temperature of 70 °C, and a catalyst concentration of 1.2 ml. The experimental yield for jatropha biolubricant with H2SO4 and HCl catalysts was measured at 226 ml and 238 ml, respectively, while the model predicted yield was 221 ml and 231 ml, respectively. The experimental yield for jojoba biolubricant with H2SO4 and HCl catalysts was recorded at 232 ml and 248 ml respectively, whereas the model predicted yield was 226 ml and 245 ml, respectively. Based on the analysis of variance (ANOVA) results, it is evident that among the three control factors, the molar ratio significantly influences the yield of both jatropha and jojoba biolubricants, as indicated by a p-value of less than 5%. The percentage contribution of the molar ratio in jatropha biolubricant with H2SO4 and HCl catalysts is found to be 98.99% and 97.2%, respectively. Furthermore, the R2 value, which exceeds 90%, signifies a strong relationship between the independent and dependent variables. The deviation between the experimental and regression-predicted equations for the yield remains within 2.5% for all combinations of jatropha and jojoba biolubricants. In conclusion, the study successfully prepared biolubricants from jatropha and jojoba-based non-edible vegetable oils and determined the optimal conditions for their production. [ABSTRACT FROM AUTHOR]

The application of non-noble metal catalysts in the catalytic direct gas-phase epoxidation of propylene with H2 and O2 to produce propylene oxide is valuable and challenging. The introduction of alkali metal promoters is one of the effective methods to improve the catalytic activity of catalysts. Herein, a series of alkali metal (Li, Na, K, Rb, and Cs)-promoted Ni/TS-1 catalysts were prepared to deeply understand the effect of alkali metals on the structure-activity relationship for gas-phase epoxidation of propylene. Among them, the Na-Ni/TS-1 catalyst exhibits the highest catalytic activity (propylene conversion of 7.35% and PO formation rate of 157.9 g h−1 kgcat−1) and the best stability (long-term stability exceeding 140 h at 200 °C). X-ray absorption and photoelectron spectroscopy revealed that the electronic structure of Ni can be tuned by the addition of alkali metal promoters. NH3-TPD-MS, CO2-TPD-MS, and C3H6-TPD-MS results indicate that the acidity of the catalyst can also be adjusted by the introduction of alkali metal, whereas the Na-Ni/TS-1 catalyst exhibits the strongest C3H6 adsorption capacity. Thus, the suitable acid-base properties, unique electronic properties of Ni species, and the strongest propylene adsorption capacity resulted in improved propylene gas-phase epoxidation activity of Na-Ni/TS-1 catalyst. This study not only provides a new strategy for the practical application of nickel-based catalysts in the gas-phase epoxidation of propylene but also provides insights into the promoting effect of alkali metals. [ABSTRACT FROM AUTHOR]

Titanosilicate with H2O2 stands out as a highly consequential oxidized catalytic system, prized for its user‐friendly operation, mild conditions, and eco‐friendly attributes. However, a synthesis strategy for large surface area titanosilicalites approaching the theoretical lowest Si/Ti ratio without extra‐framework Ti species remains an ongoing challenge. In this study, we successfully synthesized single‐crystalline Ti‐rich nanosized aggregated TS‐1 by shielding effect with a Si/Ti polymer. This polymer demonstrated effectiveness in restraining TiO2 species by regulating the proximity of Si/Ti species in Ti‐Diol‐Si polymers. The polymer not only facilitated the synthesis of single‐crystalline Ti‐rich TS‐1 but also exploited the chain length of PEG, functioning as a shielding cage by hydrogen bonds, to synthesize nanosized aggregated TS‐1 (TS‐1‐PEG400). This TS‐1‐PEG400 exhibited superior conversion (~60%), selectivity (~90%), and stability in 1‐hexene epoxidation. This study not only establishes a synthesis pathway for Ti‐rich TS‐1 but also holds the potential to enhance related industrial oxidation reactions involving titanosilicates and H2O2. [ABSTRACT FROM AUTHOR]

Owing to the increasing demands for eco‐friendly epoxides derived from vegetable oils, much effort has been made regarding the epoxidation of oleic acid in recent years. However, to date, there is a paucity of studies on the autocatalytic epoxidation specifically epoxidized oleic acid as it is not fully utilized. The autocatalytic epoxidation of oleic acid was carried out by using in situ generated performic acid to produce epoxidized oleic acid. Performic acid was formed by mixing formic acid (as oxygen carrier) and hydrogen peroxide (as oxygen donor). A maximum relative conversion to oxirane (RCO) achieved was 87% at optimal formic acid molar ratio to oleic acid under following conditions: (1) reaction temperature: 75°C, (2) stirring speed: 300 rpm, (3) formic acid/oleic acid molar ratio: 2.5, and (4) hydrogen peroxide/oleic acid molar ratio: 1.0. The degradation of epoxidized oleic acid after oxirane ring opening invites hydroxylation reaction take place called alcoholysis and hydrolysis. The hydroxyl value from alcoholysis was 346.9 mg KOH/g while the hydroxyl value of hydrolysis was 296.4 mg KOH/g using autocatalyzed reaction. In conclusion, high and low hydroxyl value has their own benefits as intermediate product for polymer application such as flexible polyurethane and rigid polyurethane. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the effects of different types of catalysts – sulphuric acid titanium dioxide, and Amberlite – and to investigate the effect of catalyst loading (0.1 g, 0.5 g, 1.0 g) on the relative conversion to oxirane (RCO %). This study examines the influence of these different catalyst types and their loadings on the epoxidation of palm oil to identify the optimum conditions for the process. The epoxidised palm oil was analysed using RCO % and Fourier transform infrared spectroscopy (FTIR). The results showed that 0.5 g sulphuric acid as a catalyst with a loading of 0.5 g achieved the highest RCO % at 76.16 %. FTIR spectra revealed the presence of an epoxy group at 833.10 cm–1. In conclusion, using 0.5 g of sulphuric acid as the catalyst provides the optimum conditions for the epoxidation process.

旨在为环氧棉籽油的制备及其高附加值利用提供理论依据和技术支撑，分别采用无机强酸催化法和有机酸自催化法对棉籽油进行环氧化，考察了不同酸对环氧化反应的催化作用及乳化剂对环氧化工艺的影响。以环氧棉籽油为原料，采用开环一锅法制备羟基化棉籽油，并将其与己二酸发生酯化反应合成棉籽油聚酯，对产物进行了红外光谱和核磁共振氢谱表征。结果表明：无机酸中浓硫酸对棉籽油环氧化的催化效果最佳，其次是磷酸，有机酸中甲酸效果最优；乳化剂增加了油-水体系的均匀混合，可适当提高产品的环氧值，但需增加破乳工段；棉籽油聚酯中存在酯基，但仍有未酯化的羟基。综上，量化生产环氧棉籽油可优先考虑甲酸为催化剂，通过环氧棉籽油制备羟基化棉籽油，再与多元酸反应可制备棉籽油聚酯，但存在未酯化的羟基。In order to provide theoretical basis and technical support for the preparation and high value-added utilization of epoxy cottonseed oil,cottonseed oil was epoxidized by inorganic acid catalysis and organic acid autocatalysis. The catalytic effect of different acids on the epoxidation reaction and the influence of emulsifiers on the epoxidation process were investigated. Hydroxylated cottonseed oil was prepared using epoxy cottonseed oil as raw material by open-loop one pot synthesis method, and then esterified with adipic acid to synthesize cottonseed oil polyester. The product was characterized by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance. The results showed that concentrated sulfuric acid had the best catalytic effect on the epoxidation of cottonseed oil, followed by phosphoric acid in inorganic, and formic acid in organic acids had the best effect. Emulsifiers increased the uniform mixing of the oil-water reaction system and appropriately increased the epoxy value of the product. However, an additional step of demulsification was not suitable for quantitative production. Cottonseed oil polyester had ester groups, but still had unesterified hydroxyl groups. In conclusion, quantitative production of epoxy cottonseed oil can prioritize formic acid as a catalyst, and hydroxylated cottonseed oil prepared by epoxy cottonseed oil can react with polyacids to prepare cottonseed oil polyester, but there are still unesterified hydroxyl groups.

The electrochemical propylene epoxidation reaction (PER) provides a promising route for ecofriendly propylene oxide (PO) production, instantly generating active halogen/oxygen species to alleviate chloride contamination inherent in traditional PER. However, the complex processes and unsatisfactory PO yield for current electrochemical PER falls short of meeting industrial application requirements. Herein, a spatial‐coupling strategy over RuO2/Ti hollow‐fiber penetration electrode (HPE) is adopted to facilitate efficient PO production, significantly improving PER performance to ampere level (achieving over 80 % PO faradaic efficiency and a maximum PO current density of 859 mA cm−2). The synergetic combination of the penetration effect of HPE and the spatial‐coupled reaction sequence, enables the realization of ampere‐level PO production with high specificity, exhibiting significant potentials for economically viable PER applications. [ABSTRACT FROM AUTHOR]

The rational design of isolated metals containing zeolites is crucial for the catalytic conversion of biomass‐derived compounds. Herein, we explored the insertion behavior of the isomorphic substitution of Ti(IV) in different zeolite frameworks, including ZSM‐35 (FER), ZSM‐5, and BEA. The different aluminium topological densities of each zeolite framework lead to the creation of different degrees of vacant sites for hosting the tetrahedrally coordinated Ti(IV) active sites. These observations show the precise control of the degree of four‐coordinated Ti(IV) sites in a zeolite framework, especially in BEA topology, by tuning the degree of unoccupied sites in the host zeolite structure via dealumination. Interestingly, the more vacancies in the host zeolite structure, the more isolated tetrahedrally coordinated Ti(IV) can be increased, eventually enhancing the catalytic performance in methyl oleate (MO) epoxidation for producing methyl‐9,10‐epoxystearate (EP). The engineered Ti‐β exhibits outstanding performances in bulky MO epoxidation with the amount of produced EP per number of Ti sites up to 17.1±1.8 mol mol−1. This observation discloses an alternative strategy for optimizing catalyst efficiency in the rational design of the Ti‐embedding zeolite catalyst, endeavoring to reach highly efficient catalytic performance. [ABSTRACT FROM AUTHOR]

Production of epoxides via selective oxidation of olefins affords a fundamental source of key intermediates for the industrial manufacture of diverse chemical stocks and materials. Current oxidation strategy generally works under harsh conditions including high temperature, high pressure, and/or request for potentially hazardous oxidants, leading to substantial challenges in sustainability and energy efficiency. To this end, direct electrocatalytic epoxidation poses as a promising solution to these issues, yet their industrial applications are limited by the low selectivity, low yield, and poor stability of the electrocatalysts. Here we report a universal electrochemical epoxidation approach via a kinetically confined surface radical pathway. High epoxidation efficiency can be achieved under mild working conditions (e.g., >99% selectivity, >80% yield and >80% Faraday efficiency for cyclohexene-to-cyclohexene oxide conversion), which can be extended to broad scope of olefin substrates. The catalytic performance originated from a surface bimolecular (L-H) reaction mechanism involving formation and surface confinement of bromine radicals due to kinetic restriction, which effectively activates inert C=C bonds while avoiding the homogenous radical side reactions. With the use of renewable energy and water as green oxygen source, successful implementation of this approach will pave the way for more sustainable chemical production and manufacturing. The industrial application of direct electrocatalytic epoxidation of olefins is limited by the low selectivity, low yield, and poor stability of the electrocatalysts. Here the authors report a universal electrochemical epoxidation approach via a kinetically confined surface radical pathway. [ABSTRACT FROM AUTHOR]

Hierarchically structured materials are considered to be one of the important options to enhance the mass transportation efficiency in microporous zeolites. Herein, we reported a highly efficient steam-assisted crystallization strategy for the synthesis of a hierarchical TS-1 zeolite with a tunable macropore size. The amorphous SiO2–TiO2 precursor dissolved gradually and acted as both a nutrient supplier and macropore template in situ. The framework Ti content of the synthesized TS-1 zeolites could be tuned over a wide range (Ti wt% = 0.70–1.39) by varying the Ti content of the SiO2–TiO2 precursor. Moreover, the pore size of the macropores could be modulated according to the particle size of the precursor based on the investigation of the formation mechanism of the macropores in the hierarchical TS-1 zeolite. The hierarchical TS-1 zeolite exhibited better catalytic activity in the epoxidation reaction of 1-hexene and hydroxylation of phenol compared to the typical microporous zeolites. The improved performance of the hierarchical TS-1 zeolite was probably caused by the improved diffusion performance of the hierarchical structure. [ABSTRACT FROM AUTHOR]

AbstractThe efficient asymmetric dihydroxylation of 6,7-epoxygeraniol was performed using a chemoenzymatic process employing a yeast epoxide hydrolase (EH) resolution stereoinversion step, followed by stereoretentive chemical hydrolysis of the remaining epoxide to produce (6 R)-6,7-dihydroxygeraniol at unprecedented high enantiometic excess (ee) (>97.5%) and high isolated yield (72 mol % overall yield over 5 steps from commercially available geraniol). The enzymatic process was completed within 2 h at 250 g/L substrate loading reaching > 49.5 mass % conversion of the racemic epoxide. The reaction was self-limiting and furnished both the homochiral (6 R)-triol and the residual (6 R)-epoxide at > 99% ee, due to enantio-inversion of the (6S)-epoxide. The (6 R)-epoxide was subsequently chemically hydrolysed, without first needing to separate the epoxide and triol products, to afford the desired (6 R)-triol product in >97.5% ee, at multigram scale. This chemoenzymatic procedure offers an excellent alternative to chemical asymmetric epoxidation or dihydroxylation for the production of enantiopure 6,7-dihydroxygeranyl and 6,7-epoxygeranyl type compounds in general. It exemplifies the benefits of using greener EH bioprocesses to produce such compounds in high ee’s and high isolated yields. [ABSTRACT FROM AUTHOR]

A selective and efficient olefin epoxidation has been developed by Fe3O4@SiO2/(TEMPO)-copolymer-(Chlorophyll b)-Co(III) NPs as a heterogeneous magnetically recyclable nanocatalyst. The nanocatalyst was synthesized through several steps including chlorophyll b de-metallation, imine functionalization with ally amine, co-polymerization with acrylated TEMPO, re-metalation with cobalt, and immobilization on magnetite NPs. Selective catalytic epoxidation of olefins was accomplished under mild conditions and in an O2 atmosphere. High selectivity and conversion were achieved for a variety of substrates. The results indicated a synergistic effect between TEMPO moieties and the coordinated Co(III) centers as two active sites. The epoxide products could be separated by the heterogeneous poly(benzoic acid) with the highest possible isolated yields. Also, the heterogeneous nanocatalyst could be recycled for at least 7 consecutive cycles with a negligible reactivity loss. A selective and efficient olefin epoxidation with smart isolation has been developed by Fe3O4@SiO2/(TEMPO)-copolymer-(Chlorophyll b)-Co(III) NPs under mild conditions. [ABSTRACT FROM AUTHOR]

The competitiveness of the biodiesel industry and the evolution of its positive socio-environmental externalities may be achieved by adding value to oleochemical by-products to be produced in an integrated way with the production of biodiesel. The development of bio-based lubricants, a substitute for mineral lubricating oils, has emerged as a promising alternative for adding value to vegetable oils, and consequently to biodiesel. This study presents a comprehensive assessment of biolubricant production using biodiesel as a feedstream, employing epoxidation and oxirane ring opening reactions with 2-ethylhexanol (BL1) and water (BL2) as nucleophilic agents. Industrial processes were proposed and simulated for two scenarios, considering all steps for production of BL1 (26.6 cSt at 40 °C and pour point of − 12 °C) and BL2 (99.6 cSt at 40 °C and pour point of − 3 °C). The biolubricant production showed promising profitability, as its minimum selling price (MSP) remained consistently below USD 3000/ton, significantly lower than the average price of mineral lubricants (USD 6000/ton). Both scenarios exhibited minimal variation in the MSP of biolubricants (< 2%). The estimated high internal rates of return (24.5% for scenario 1 and 18.6% for scenario 2) highlight the potential profitability of this technological route, even under very conservative perspectives. A technical–economic analysis of an integrated biodiesel and biolubricant production system demonstrated significant synergies during the installation and operational stages, resulting in 21% Capex savings when retrofitting an existing biodiesel plant for biolubricant co-production. Notably, for various combinations of biolubricant prices above USD 3000/ton, the MSP of biodiesel became lower than the specified price of mineral diesel. These findings indicate the potential of integrating biolubricant and biodiesel production as a strategic approach to enhance the biodiesel competitiveness and maximize its positive externalities on society, economy, and environment. [ABSTRACT FROM AUTHOR]

Government initiatives, price cuts, and innovations in technology have caused a shift in the world's raw material consumption towards renewable materials. The polymer industry has shown particular interest in studies on more environmentally friendly epoxidation processes that use vegetable oils. Epoxidized vegetable oils are renewable, affordable, and eco‐friendly, which makes them a promising green material to partially replace and toughen polymers derived from petrochemicals. Using a kinetic model from the literature, this study develops a system of fractional‐order differential equations to investigate the significance of oleic acid epoxidation. With oleic acid serving as the primary raw material, the study focuses on producing epoxidized oleic acid with a high yield and a longer reaction time. We apply both qualitative and quantitative analysis to the model using fixed‐point theorems. The model's Ulam–Hyers stability is established. Investigation of the fractional operator's effect is done through computational simulations and the Laplace Adomian decomposition technique. The investigation of the effects of fractional operators on the epoxidation process reveals that temperature, molar ratios, and fractional order are significant determinants of the process. [ABSTRACT FROM AUTHOR]

Epoxides are high‐valued intermediates in the production of chemicals, pharmaceuticals, perfumes, and polymers. Given the growing demand for epoxides, it is imperative to develop more environmental friendly and sustainable routes instead of the chlorohydrin process. Notably, the direct utilization of hydrogen peroxide (H2O2) for the epoxidation reaction presents significant advantages from both environmental and economic perspectives. The review provides insights into both homogeneous and heterogeneous catalysts employed in the 1‐butene epoxidation using the green oxidant H2O2. Among the diverse range of catalysts, titanosilicate‐1 (TS‐1) has garnered extensive attention due to its exceptional selectivity and high oxygen atom utilization. The aim of this review is to illustrate various strategies for TS‐1 catalysts preparation that can lead to more versatile, higher‐performance, and greener epoxidation processes. Additionally, various potential approaches to enhance the catalyst performance of TS‐1 are highlighted, including (i) constructing specific coordination modes of Ti sites, (ii) regulating the microenvironment around Ti sites, and (iii) improving the accessibility of Ti sites. Furthermore, advances in molding TS‐1 catalysts are also introduced from the perspective of the industrialization. Finally, future research directions are discussed with emphasis on the application scope of TS‐1 to gain deeper insights into epoxidation process. [ABSTRACT FROM AUTHOR]

The efficient synthesis of an array of 1‐aryloxy‐1,1‐difluoro‐3‐aminopropan‐2‐ols in a one‐pot epoxidation/nucleophilic ring‐opening via the corresponding iodohydrines is described. This methodology permits the construction of 1,1‐difluorinated derivatives of commercialized beta‐blockers in addition to unprecedented members of this compound class. [ABSTRACT FROM AUTHOR]

Conformational freedom-restricted peptides, such as stapled peptides, play a crucial role in the advancement of functional peptide development. We synthesized stapled octapeptides using α-carbocyclic α,α-disubstituted α-amino acids, particularly 3-allyloxy-1-aminocyclopentane-1-carboxylic acid, as the crosslink motifs. The organocatalytic capabilities of the synthesized stapled peptides were assessed in an asymmetric nucleophilic epoxidation reaction because the catalytic activities are known to be proportional to α-helicity. Despite incorporating side-chain crosslinks, the enantioselectivities of the epoxidation reaction catalyzed by stapled octapeptides were found to be comparable to those obtained using unstapled peptides. Interestingly, the stapled peptides using α-carbocyclic α,α-disubstituted α-amino acids demonstrated higher reactivities and stereoselectivities (up to 99% ee) compared to stapled peptides derived from (S)-α-(4-pentenyl)alanine, a commonly used motif for stapled peptides. These differences could be attributed to the increased α-helicity of the former stapled peptide in contrast to the latter, as evidenced by the X-ray crystallographic structures of their N-tert-butoxycarbonyl derivatives. [ABSTRACT FROM AUTHOR]

The machining process is considered a basic procedure in any mechanical-based industry. Machining is the interaction between the tool and the raw material that results in material deformation and thus leads to heat generation in the work zone, and chip formation. Thus, for metal working operations, lubricants commonly employed are generally known as metal working fluids (MWFs). Besides lubrication, MWFs remove heat generated in the work zone, and the chips that form will be carried away. The widely available mineral oil–based MWFs are non-biodegradable and also cause several health disorders to the operator involved, which necessitates the need for biodegradable cutting fluids (CFs). The base-stock for the green cutting fluid (GCF) in this work is rice bran oil (RBO). The poor oxidation stability of the RBO is addressed by chemical modification method. Then clove oil was added as a bio-additive to further enhance the lubricant properties of chemically modified RBO. The performance of the GCF formulated was evaluated and compared with commercial cutting fluid using a pin on disc apparatus. The formulated green cutting fluid is observed to be better in terms of coefficient of friction, corrosion and oxidation stability with comparable performance test results. [ABSTRACT FROM AUTHOR]

Epoxidation of oleic acid from vegetable oil has become popular due to the high demand for environmentally friendly epoxides from vegetable oils nowadays. This study aims to investigate the synthesis of epoxidized hybrid oleic acid from waste palm cooking oil and palm oil via in situ peracid mechanism. The novel method using hybrid raw material which is palm oil and waste palm cooking oil was introduced in this study in the epoxidation with performic acid in the presence of sulfuric acid as a homogeneous catalyst. Based on ideal process parameters, the maximum conversion to oxirane can be up to 65% using the optimum process parameter with a temperature of 75℃ and sulfuric acid act as catalyst. A mathematical model was developed by using the numerical integration Runge Kutta 4th Order method. The results showed that there was good agreement between the simulation and experimental data, which validates the kinetic model. [ABSTRACT FROM AUTHOR]

Mycoparasite secondary metabolites control fungal infections or diseases in agriculture and human health. Among genes involved in synthesizing secondary metabolites, cytochrome P450 monooxygenases (CYPs/P450s) play a key role in synthesizing and attributing diversity to the secondary metabolites. Despite the importance of P450s, a comparative analysis of P450s in mycoparasites has yet to be reported. This study is aimed at addressing this research gap. Genome-wide analysis of P450s in 43 fungi representing six fungal phyla and three distinct lifestyles, such as mycoparasitic (24 species), saprophytic (5 species), and ectomycorrhizal (14 species), revealed the expansion of P450s in Pezizomycete mycoparasites for the synthesis of secondary metabolites. The number of P450s and their families and subfamilies, the number of secondary-metabolite biosynthetic gene clusters (SMBGCs), and the number of P450s that are part of these SMBGCs were found to be highest in Pezizomycete mycoparasites compared to their counterparts of saprophytes and ectomycorrhiza, indicating P450s also play a key role in mycoparasitism. An analysis of P450 location as part of SMBGCs and the available literature on Pezizomycete P450s revealed that P450s play a key role in the synthesis of anti-fungal secondary metabolites such as trichothecene sesquiterpene, harzianum A, heptelidic acid, and gliotoxin. The mycoparasite Trichoderma virens Tv29.8 P450 CYP68Q3 is found to be a bifunctional enzyme with epoxidation and oxidation capability, and CYP5117A3 performs a Baeyer–Villiger oxidation reaction with regioselectivity. This study serves as a reference for future annotation of P450s in mycoparasites. [ABSTRACT FROM AUTHOR]

The aim of this work was to the obtaining novel mixed-mode stationary phases with increased hydrophilicity and applying them in ion and hydrophilic interaction liquid chromatography. The resins were obtained by the sequential covalent attachment of branched polyethylenimine and polyelectrolytes synthesized from diepoxide and a secondary amine on the surface of epoxidized polystyrene–divinylbenzene. To increase the shielding degree of the polymer substrate, an additional polymerization of glycidol was carried out in the functional layer of the sorbent at an increased pH of the reaction medium. The synthesized phases possessed increased hydrophilicity compared to most resins based on a styrene–divinylbenzene copolymer with covalently attached layers. This was evidenced in the ion chromatography mode by a decrease in the relative retention of polarizable anions, weakly hydrated oxyhalides (up to a change in the elution order of the bromate), and haloacetic acids. In the hydrophilic interaction liquid chromatography mode, an increased hydrophilicity of the phases was confirmed by an increase in the retention factors of polar analytes, as well as by the reversal of the elution order of ascorbic and nicotinic acids as compared to the phases based on polystyrene–divinylbenzene presented in the literature. The low efficiency of the obtained stationary phases in the ion chromatography mode was noted, which is associated with slow mass transfer in the bulk polymer functional layer. The negative impact of the polymer layer on efficiency in hydrophilic interaction liquid chromatography is less pronounced due to the presumably smaller thickness of the part of the functional layer involved in this mode. The proposed method for the synthesis of resins ensures an increase in the efficiency, selectivity, and separation ability of sorbents in the hydrophilic interaction liquid chromatography mode as compared to phases based on a styrene–divinylbenzene copolymer described previously in the literature. The resulting highly hydrophilic resins makes it possible to separate a mixture of 9 nitrogenous bases and nucleosides in 18 min, 6 vitamins in 24 min, and 8 sugars in 11 min. Thus, the method of substrate hydrophilization proposed in this work is promising for improving the chromatographic characteristics of phases in the hydrophilic interaction liquid chromatography mode and can be used to create sorbents with increased selectivity and efficiency. [ABSTRACT FROM AUTHOR]

In this study, synthesis, characterization and photopolymerization of new type of castor oil-based monomer family are studied. Electrical properties of the synthesized polymers are also evaluated. The synthesis of these materials consists of two steps. Acrylation of the castor oil and methyl ricinoleate occur in the first step and epoxidation is then followed. Epoxidized acrylated castor oil (EACO) and epoxidized acrylated methyl ricinoleate (EAMR) are synthesized at the end of the reactions. FTIR (Fourier transform infrared) and 1H NMR (nuclear magnetic resonance) spectroscopy techniques are used to characterize of the starting materials and monomers. When acrylate groups are introduced to castor oil and methyl ricinoleate, a characteristic peak at 1722 cm−1 is observed in FTIR spectrum and peaks of acrylate hydrogens at 5.7, 6.0 and 6.3 are observed in 1H NMR spectrum. After epoxidation, a small peak is detected at 840 cm−1 in FTIR spectrum and new peaks appear at 2.5 and 3.0 ppm in 1H NMR spectrum. Photopolymerization of the synthesized materials are performed with DMPA (2,2-dimethoxy-2-phenylacetophenone) and AIBN (azobisisobutyronitrile) catalyst. It is found that DMPA catalyst is more effective than AIBN. EACO samples' DC (direct current) resistance and conductance values are measured as 146.4 MΩm and 6.83 nS/m, respectively, whereas EAMR samples' DC resistance and conductance values are calculated as 96 MΩm and 10.42 nS/m, respectively. AC (alternative current) analysis is conducted by using LCR meter for the polymeric samples where EACO samples' capacitances varies from 4.88 to 3.29 pF (picofarads) with respect to frequency (10 Hz–300 kHZ). On the other hand, EAMR samples' capacitances varies from 14.7 to 6.49 pF with respect to frequency. Impedance values of the EACO samples with respect to frequency are measured as 4.24 GΩ and 165 kΩ, respectively. Impedance values of the EAMR samples with respect to frequency are measured as 1.19 GΩ and 82 kΩ, respectively. [ABSTRACT FROM AUTHOR]

The demand for bio-based lubricants has grown considerably in recent years due to increasing environmental awareness among the public, governments, and industries. In this study, soybean-oil-based samples were synthesized via reactions of hydrolysis (FFA, yield > 93% wt.), esterification (BL1, yield > 92% wt.), epoxidation (BL2, yield > 91% wt.), and oxirane ring opening (BLOR, yield > 93% wt.), using a long chain alcohol (2-ethylhexanol). The obtained BL1 and BLOR samples were further subjected to tribological testing in the four-ball configuration. The friction coefficients of the BL1 and BLOR samples were evaluated using speed ramps at different loading forces and temperatures. A hydrotreated mineral oil (HMO) sample was used as a reference to evaluate the lubrication performance of the synthesized bio-based samples. The results indicated that these BL1 and BLOR samples had lower friction coefficients than HMO at all assessed sliding speeds, even with increasing load force and temperature. In the test to evaluate the wear, the samples of BL1 and BLOR presented coefficient of friction smaller than HMO in the order of 31.7% and 46.0%, respectively. Furthermore, an assessment of the wear morphologies indicated that the BL1 and BLOR samples yielded smoother surfaces with shallower grooves than the hydrotreated mineral oil sample. Among the studied bio-based lubricants, BLOR yielded the lowest friction coefficients, wear scar diameter, and surface ripples. The tribology resulting from BL1 and BLOR infers that these biolubricants have potential for applications in mechanical systems. [ABSTRACT FROM AUTHOR]