Alkyl Methyl Research Articles

Ultrasound-assisted cloud point microextraction of certain preservatives in real samples and determination by HPLC.

Ultrasound-assisted cloud point microextraction (UA-CPME) was performed for certain preservatives (p-hydroxy benzoic acid and its alkyl esters, methyl, ethyl, propyl and butyl parabens). Then, an HPLC method was developed for their simultaneous determination in pharmaceutical and cosmetic samples. The chromatograms of these substances were recorded on a C18 column using a gradient elution technique with various solvent systems at different flow rates and at 254 nm wavelength using a diode-array detector (DAD). The analysis conditions found by the classical method were optimized using the Box-Behnken design (BBD). In the design, the effect of each factor was examined with 3 and 4 factors for UA-CPME and HPLC analyses, respectively. The brij 58 concentration (BC), Na2SO4 amount (SA) and extraction time (ET) for UA-CPME, and the mobile phase 1 (MP1) ratio, mobile phase 2 (MP2) ratio, flow rate (FR) and column temperature parameters for HPLC analysis were obtained for the investigated levels. The factors affecting the resolution were determined by applying regression analysis to the experimental results. The analysis of variance (ANOVA) test was applied to ensure result reliability. The ANOVA test was used to determine the reliability of the results. A model was created with the obtained data. The developed method was validated by examining linearity, reproducibility, accuracy, limit of quantification and limit of the detection. Methyl paraben (with 0.148% RSD value and 0.060% relative error), and propyl paraben (with 0.149% RSD value and 0.120% relative error) were determined in the syrup sample by the developed method. Methyl paraben with recovery values of (98.32-99.42)% and ethyl paraben with recovery values of (99.17-99.41)%, were determined in a hand cream.

Reversible C-C Bond Formation, Halide Abstraction, and Electromers in Complexes of Iron Containing Redox-Noninnocent Pyridine-imine Ligands.

The exploration of pyridine-imine (PI) iron complexes that exhibit redox noninnocence (RNI) led to several interesting discoveries. The reduction of (PI)FeX2 species afforded disproportionation products such as (dmpPI)2FeX (dmp = 2,6-Me2-C6H3, X = Cl, Br; 8-X) and (dippPI)2FeX (dipp = 2,6-iPr2-C6H3, X = Cl, Br; 9-X), which were independently prepared by reductions of (PI)FeX2 in the presence of PI. The crystal structure of 8-Br possessed an asymmetric unit with two distinct electromers, species with different electronic GSs: a low-spin (S = 1/2) configuration derived from an intermediate-spin S = 1 core antiferromagnetically (AF) coupled to an S = 1/2 PI ligand, and an S = 3/2 center resulting from a high-spin S = 2 core AF-coupled to an S = 1/2 PI ligand. Calculations were used to energetically compare plausible ground states. Polydentate diazepane-PI (DHPI) ligands were applied to the synthesis of monomeric dihalides (DHPI)FeX2 (X = Cl, 1-Cl2; X = Br, 1-Br2); reduction generated the highly distorted bioctahedral dimers (DHPA)2Fe2X2 ((3-X)2) containing a C-C bond formed from imine coupling; the monomers 1-X2 could be regenerated upon Ph3CX oxidation. Dihalides and their reduced counterparts were subjected to various alkyl halides and methyl methacrylate (MMA), generating polymers with little to no molecular weight control, indicative of simple radical-initiated polymerization.

A Short Review on Catalyst, Feedstock, Modernised Process, Current State and Challenges on Biodiesel Production

Biodiesel, comprising mono alkyl fatty acid esters or methyl ethyl esters, is an encouraging option to fossil fuels or diesel produced from petroleum; it has comparable characteristics and its use has the potential to diminish carbon dioxide production and greenhouse gas emissions. Manufactured from recyclable and sustainable feedstocks, e.g., oils originating from vegetation, biodiesel has biodegradable properties and has no toxic impact on ecosystems. The evolution of biodiesel has been precipitated by the continuing environmental damage created by the deployment of fossil fuels. Biodiesel is predominantly synthesised via transesterification and esterification procedures. These involve a number of key constituents, i.e., the feedstock and catalytic agent, the proportion of methanol to oil, the circumstances of the reaction and the product segregation and purification processes. Elements that influence the yield and standard of the obtained biodiesel encompass the form and quantity of the feedstock and reaction catalyst, the proportion of alcohol to feedstock, the temperature of the reaction, and its duration. Contemporary research has evaluated the output of biodiesel reactors in terms of energy production and timely biodiesel manufacture. In order to synthesise biodiesel for industrial use efficaciously, it is essential to acknowledge the technological advances that have significant potential in this sector. The current paper therefore offers a review of contemporary progress, feedstock categorisation, and catalytic agents for the manufacture of biodiesel and production reactors, together with modernised processing techniques. The production reactor, form of catalyst, methods of synthesis, and feedstock standards are additionally subjects of discourse so as to detail a comprehensive setting pertaining to the chemical process. Numerous studies are ongoing in order to develop increasingly efficacious techniques for biodiesel manufacture; these acknowledge the use of solid catalytic agents and non-catalytic supercritical events. This review appraises the contemporary situation with respect to biodiesel production in a range of contexts. The spectrum of techniques for the efficacious manufacture of biodiesel encompasses production catalysed by homogeneous or heterogeneous enzymes or promoted by microwave or ultrasonic technologies. A description of the difficulties to be surmounted going forward in the sector is presented.

Imidazolium-based protic ionic liquids with perfluorinated anions: Influence of chemical structure on thermal properties

The influence of the cation chemical structure, namely its side chain, on the thermal properties of imidazolium-based protic ionic liquids (PILs) with different perfluorinated anions (trifluoromethanesulfonimide (TFSI), trifluoromethanesulfonic (TFS), and trifluoroacetic (TFA) acids) was studied. With that purpose, twenty-one PILs with various alkyl (methyl-, ethyl-, butyl- and vinyl-) and fluorinated (-CH2CF3, -CH2CHF2, and -CH2CH2F) side chains were successfully synthesized. Special attention was paid to an optimization of their synthesis conditions. The structure of synthesized fluorinated and alkyl-substituted PILs was confirmed by means of nuclear magnetic resonance (NMR) analysis (1D: 1H, 19F, 13C and 2D: 1H – 19F HOESY experiments) and Fourier transform infrared (FTIR) spectroscopy, while PILs thermal behavior was determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) in dynamic and isothermal modes. The correlation between the PILs chemical structure and their thermal stability was established. It has been found that an increase of the length of alkyl side chain (methyl- < vinyl- < ethyl- < butyl-) leads to a lower melting point temperature. Moreover, it is shown that an increase in the amount of fluorine atoms in the cation chemical structure (-CH2F < -CHF2 < -CF3) leads to a PIL with a higher crystallinity (a higher melting point temperature) and a lower thermal stability. Thus, the best performance in terms of the thermal stability was reached for monofluorinated- (-CH2F) and butyl-TFSI PILs in liquid state: 370 °C and 400 °C, respectively, while the lowest thermal stability was obtained for trifluorinated- (-CF3) and vinyl-TFA PILs in solid state: 145 °C and 129 °C, respectively.

Effect of the nO → π*C═O Interaction on the Conformational Preference of 1,3-Diketones: A Case Study of Riolozatrione Derivatives.

The cyclopropane ring-opening reaction of riolozatrione, a natural product obtained from Jatropha dioica, afforded a 2,2-disubstituted 1,3-cyclohexandione displaying an alkyl methyl ether group at position 5. The conformational analysis of this product showed a high preference for the trans-diaxial conformation in both solution and solid state. Such conformation was possible from the noncovalent intramolecular nX → π*C═O interactions (X = an element having an unshared electron pair), allowing the determination of the interaction energies. Since the nX → π*C═O interactions can be regarded as additive, the energy values ranged from 4.52 to 6.51 kcal mol-1 for each carbonyl group with a strong dependency on the interatomic distances. The rigorous analysis of the electron density in the topological theory of atoms in molecules framework clearly shows that the origin of O-C═O interactions are through the nO → π*C═O electron transfer mechanism. Such interactions are slightly weaker than a canonical hydrogen bond but seemingly stronger than a van der Waals interaction. This interaction must be considered as a stereoelectronic effect due the electronic transfer between the interacting groups, which are limited by their relative stereochemistry and can be represented by a bond-no bond interaction, causing the pyramidalization of the carbonyl, which is the charge acceptor group.

The Role of Chain Length in Cucurbit[8]uril Complexation of Methyl Alkyl Viologens

AbstractViologens are among the most studied guests for cucurbit[8]uril (CB[8]) and their complexation is usually driven by bipyridyl core inclusion inside the cavity to maximize both hydrophobic and cation‐dipole interactions. The presence of alkyl substituents on the guest alters this complexation mode, switching to aliphatic chain inclusion in U‐folded conformation. Herein, we report a thorough study of the influence of the alkyl chain length on the binding mode of methyl alkyl viologens. The chain length of the studied guests was increased by two methylene groups starting from methyl dodecyl viologen (MVC12) to the octadecyl analogue (MVC18). Complexation in water, investigated by NMR spectroscopy and ITC, revealed a clear switch from 1 : 1 to 2 : 1 host/guest stoichiometry moving from 12 to 16 carbon atoms, as a consequence of the chain folding of the major portion of the longer alkyl chain in one CB[8] cavity and the inclusion of the full viologen unit by another host molecule. The CB[8]2.MVC18 complex crystal structure evidences the unprecedented 2 : 1 stoichiometry and quantified in 12 the number of carbon atoms necessary to fill the CB[8] cavity in U‐shaped conformation.

Effects of Alkyl-Substituted Polybenzoxazines on Tribological Properties of Non-Asbestos Composite Friction Materials.

A series of substituted polybenzoxazines was synthesized and studied as binders in non-asbestos friction composite materials. The structures of the polybenzoxazines were varied in a systemic fashion by increasing the number and position of pendant alkyl (methyl) groups and was accomplished using the respective aromatic amines during the polymer synthesis step. By investigating the key thermomechanical and tribological characteristics displayed by the composite materials, the underlying structure-properties relationships were deconvoluted. Composite friction materials with higher thermomechanical and wear resistance properties were obtained from polybenzoxazines with relatively high crosslink densities. In contrast, polybenzoxazines with relatively low crosslink densities afforded composite friction materials with an improved coefficient of friction values and specific wear rates.

Short Strong Hydrogen Bonds can Hinder Complex Formation: A Stability and Structure Study of Copper(II) Alkyl-N-iminodiacetic Acid Complexes in Aqueous Systems and Solid State

In the present study the solution and coordination chemistry of copper(II)–alkyl-N-iminodiacetate systems are studied in aqueous solution by potentiometry, using ion selective copper and pH electrodes, EXAFS (extended X-ray absorption fine structure) and dye probe molecular absorption spectrophotometry. Alkyl-N-iminodiacetates with varying alkyl chain length, methyl (CH3–), n-hexyl (C6H13–), n-dodecyl (C12H25–) and n-octadecyl (C18H37–) were used to tune the amphiphilic properties of the ligands. The polar head groups have both oxygen (hard Lewis base) and nitrogen donor (border-line Lewis base) atoms. This means that metal ions with different bonding characteristics may bind these ligands differently. Furthermore, the chelating properties of the polar head group may be regulated by pH as the acid–base properties of the imine and carboxylic acid groups are different. Copper(II) forms two stable complexes with alkyl-N-iminodiacetates with short alkyl chains, present as monomers in aqueous solution, log10β1 = 11.10(2), log10β2 = 19.5(2) for methyl-N-iminodiacetate, and log10β1 = 12.22(4), log10β2 = 21.9(2) for n-hexyl-N-iminodiacetate. n-Octadecyl-N-iminodiacetic acid, present as large aggregates in acidic aqueous solution, has short strong hydrogen bonds between carboxylic acid and carboxylate groups in the surface of the aggregates, which hinder complex formation at pH values below 4, obstructs it in the pH region 4–7, while the complex formation behaves as for short-chained alkyl-N-iminodiacetates at pH > 7. The structure around copper in copper(II)–alkyl-N-iminodiacetate complexes in aqueous solution and solid state formed at different pH values and copper(II):alkyl-N-iminodiacetate ratios has been determined by EXAFS. The coordination chemistry of copper(II) shows four strong bonds in the equatorial plane, and two different Cu–O/N bond distances, ca. 0.2 Å apart, in the axial positions of a non-centrosymmetric tetragonally elongated octahedron.

Significantly improved interfacial shear strength in graphene/copper nanocomposite via wrinkles and functionalization: A molecular dynamics study

Graphene reinforced metal matrix composites (MMCs) have received extensive research interests as promising structural materials in developing lightweight structures. The mechanical performance of such composites, however, is considerably hindered by weak van der Waal (vdW) interaction between graphene and metal matrix. The present work shows that this challenging issue can be effectively alleviated by the use of chemically functionalized graphene fillers with mechanically induced wrinkles. Our extensive molecular dynamics (MD) simulations on graphene reinforced copper (Cu) composite manifest that the presence of shear-induced wrinkles and chemical modification of graphene using functional groups can significantly increase its surface roughness, enhance the vdW interaction and consequently lead to higher interfacial shear strength (IFSS) between graphene and Cu matrix. Compared with its counterpart functionalized with hydrogen, graphene functionalized with alkyl (methyl, ethyl, propyl, and butyl) offers better interfacial interactions with Cu matrix because these functional groups are longer than hydrogen functional group and can be embedded deeper into the matrix.

Synthesis and Anti proliferative Activity of New N‐Pentylquinoxaline carboxamides and Their O‐Regioisomer

AbstractWe have designed a series of quinoxalinepeptidomimetic derivatives based on our previous reported scaffold in attempt to find a promising lead compound. Quinoxaline derivatives; N‐alkyl‐3‐(3‐oxo‐4‐pentyl‐3,4‐dihydro‐quinoxalin‐2‐yl)‐propanamides and methyl 2‐[3‐(3‐oxo‐4‐pentyl‐3,4‐dihydro‐quinoxalin‐2‐yl)propanamido]alkanoates and their O‐regioisomers were prepared by alkylation of the ambient nucleophile methyl 3‐(3‐oxo‐3,4‐dihydroquinoxalin‐2‐yl)propanoate with pentyl bromide to give the corresponding N‐ and O‐pentylquinoxaline ester derivatives. The N‐ and O‐pentyl‐quinoxaline ester derivatives gave the desired products by the reaction with amines and amino acid esters via azide coupling method. We have examined the anti proliferative activity of the 35 different synthesized compounds on human HCT‐116 and HEK‐293 cell lines. Out of 35 screened derivatives, 14 active compounds exhibited inhibitory action on the HCT‐116 cells with IC50 values ranging from 0.43 mM to 2.62 mM. We have also examined the impact of these active compounds on cancer cells nucleus and caspase 3 activity, we have the found that active compounds also increased in the caspase 3 activity which led to programmed cell death of cancer cells. We have also examined the impact of 35 compounds on the normal and non‐cancerous cells (HEK‐293) and we have found these active compounds did not cause any cytotoxic effect on the normal cells.

Internal Rotation of the Acetyl Methyl Group in Methyl Alkyl Ketones: The Microwave Spectrum of Octan-2-one.

Methyl n-alkyl ketones form a class of molecules with interesting internal dynamics in the gas-phase. They contain two methyl groups undergoing internal rotations, the acetyl methyl group and the methyl group at the end of the alkyl chain. The torsional barrier of the acetyl methyl group is of special importance, since it allows for the discrimination of the conformational structures. As part of the series, the microwave spectrum of octan-2-one was recorded in the frequency range from 2 to 40 GHz, revealing two conformers, one with C1 and one with Cs symmetry. The barriers to internal rotation of the acetyl methyl group were determined to be 233.340(28) cm-1 and 185.3490(81) cm-1 , respectively, confirming the link between conformations and barrier heights already established for other methyl alkyl ketones. Extensive comparisons to molecules in the literature were carried out, and a small overview of general trends and rules concerning the acetyl methyl torsion is given. For the hexyl methyl group, the barrier height is 973.17(60) cm-1 for the C1 conformer and 979.62(69) cm-1 for the Cs conformer.

Change in the pH of NaI and methyl alkyl ketone solutions under gamma irradiation

The effects of dissolved chemicals such as NaOH, NaI, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK) on solution pH after gamma irradiation were investigated. Upon irradiation with 1.6–24 kGy of gamma radiation (0.4–6 kGy h−1), the pH of the NaOH solutions decreased, while the OH− consumption increased with increasing initial solution pH. This was attributed to acid–base neutralization between the OH− in the solutions and the acidic species (HO2· and ·NO2) formed by irradiation. The pH of the acidic NaI solution increased after irradiation with 8 kGy dose (at 2 kGy h−1), which was attributed to I− oxidation by the products of water and air radiolysis. The pH values of the MIBK and MEK solutions decreased from 7 to 4.5 or lower upon irradiation with 40 kGy dose (at 10 kGy h−1), which indicates that the alkyl groups of the ketones do not significantly affect the rates of decomposition by irradiation. The pH of the mixed solution of ketone and NaI was in the range of 6.7–6.9 before irradiation but decreased to 4.5 after irradiation with 40 kGy dose. In the mixed solutions, CH3COR and I− competed with each other to contribute to pH change.

C2-Symmetric 1,2-Diphenylethane-1,2-diamine-Derived Primary-Tertiary Diamine-Catalyzed Asymmetric Mannich Addition of Cyclic N-Sulfonyl Trifluoromethylated Ketimines.

A simple chiral primary-tertiary diamine derived from C2-symmetric 1,2-diphenylethane-1,2-diamine as the organocatalyst in combination with the trifluoroacetic acid additive for the asymmetric Mannich reaction of cyclic N-sulfonyl trifluoromethylated ketimines and methyl ketones afforded the desired product with high enantioselectivity (73-96% ee). The reactions proceeded well for a variety of different substituted cyclic N-sulfonyl trifluoromethyl ketimines and various alkyl methyl ketones, providing access to diverse enantioenriched benzo-fused cyclic sulfamidate N-heterocycles bearing a trifluoromethylated α-tetrasubstituted carbon stereocenter. This study also investigated the diastereoselective reduction of the carbonyl group and ring cleavage reduction of the sulfamidate group of the corresponding Mannich product.

Solid acid catalyzed carboxymethylation of bio-derived alcohols: an efficient process for the synthesis of alkyl methyl carbonates

Acid catalyzed carboxymethylation of alcohols is an emerging organic transformation that has grabbed the attention of scientific community in recent years. In the present study, sulfonated mesoporous polymer (MP-SO3H) is presented as a highly active solid acid catalyst to convert a wide range of alcohols into alkyl methyl carbonates. The remarkable catalytic activity of MP-SO3H is comparable to that of reported homogeneous acid catalysts. A good correlation was established between the catalytic activity and textural properties of the material. An exceptional catalytic activity of MP-SO3H was observed for DMC mediated carboxymethylation of bio-derived alcohols which is unmatchable to conventional resins and zeolites. This superior activity of MP-SO3H is ascribed to its intrinsic mesoporosity, high acid strength and uniform coverage of surface area by active sites. The catalyst is recyclable, resistant towards leaching and can be used in successive runs without losing the original activity. To the best of our knowledge, MP-SO3H is the first solid acid catalyst to exemplify highest activity for the synthesis of different alkyl methyl carbonates using DMC. The protocol developed herein opens up new avenues to transform wide range of bio-alcohols into useful organic carbonates in the future.

Structure-relation properties of N-substituted phenothiazines in solution and solid state: Photophysical, photostability and aggregation-induced emission studies

Five N-substituted phenothiazines (with different alkyl and aryl groups) were investigated aiming to rationalize the influence of the substitution in the photooxidation processes and in the aggregation induced emission (AIE) properties of these compounds. A comprehensive spectroscopic and photophysical investigation in solution (diluted in solutions of methylcyclohexane, MCH, tetrahydrofuran, THF, and in THF: water mixtures aiming to promote aggregation) and in the solid state (powder and films), with the characterization of all the excited state deactivation routes with the determination of quantum yields (fluorescence, phosphorescence and singlet oxygen sensitization), lifetimes and rate constants, was performed. Room temperature phosphorescence in the solid state was observed for the methyl and bi-phenyl derivatives. Stability upon irradiation of the compounds was further investigated and the biphenyl derivative was found stable in contrast with phenothiazine and the other alkyl (methyl and hexyl) derivatives. These were further rationalized with TD-DFT calculations. These findings present relevant information to the efficient design of photo-stable phenothiazine derivatives in light emitting applications.

Ruthenium Catalyzed Divergent Alkylation and Olefination of Methyl 1,3,5‐Triazines with Alcohols

An efficient ruthenium‐catalyzed divergent alkylation and olefination of methyl 1,3,5‐triazines with alcohols have been developed. The selectivity can be rationally tuned by the judicious choice of ruthenium catalyst, wherein Ru(PPh3)3Cl2 delivers alkylated 1,3,5‐triazines and RuCl3 gives olefinated 1,3,5‐triazines in up to 98 % yield. Following this simple, facile, and high atom economical protocol, a broad range of products was prepared in moderate to good yields and tolerated heterocyclic or benzylic alcohols containing functionalities. The overall transformation operates through dehydrogenation of primary alcohols under the reaction conditions to provide the corresponding aldehydes, which further undergo condensation with methyl 1,3,5‐triazines.

Synthesis and structure of sodium 1-alkoxy-1,4-dioxo-2-alkenolates and bis-(4-alkyl(aryl)- 1-oxo-1-alkoxyalkane-2,4-dionato) metals (II) based on them

A priority task in contemporary organic chemistry consists in the synthesis of practically useful metal complexes having carbonyl-containing ligands. The present article details the isolation of several new bis-(4-alkyl(aryl)-1-oxo-1-alkoxyalkane-2,4-dionato) metals (II) via complex formation of metal salts of (zinc (II), copper (II) and nickel (II)) with sodium 1-alkoxy-1,4-dioxo-2-alkenolates obtained by condensation of alkyl (aryl) methyl ketones with dialkyl oxalates in the presence of sodium or sodium hydride as a condensing reagent. The structure of the synthesised sodium oxoenolates and metal complexes was confirmed by spectral analysis methods (IR, NMR 1 H-, NMR 13 C-spectroscopy and mass spectrometry). In the IR spectra of the solid samples of the isolated compounds, stretching vibrations bands of ester carbonyl groups were identified, as well as high-intensity ether bands due to the vibrations of С-О-С bonds. For compounds containing aromatic fragments, bands corresponding to vibrations of monosubstituted benzene rings were found in the IR spectra. The NMR spectra of 1 H of sodium oxoenolates and metal complexes recorded in DMSO-d 6 demonstrated characteristic signals of ethoxy and n - butoxy fragments, methine protons, as well as protons of aromatic rings. Chemical shifts of carbon atoms in the NMR spectra 13 C of sodium oxoenolates correspond well to the reference values. In the mass spectra of synthesised compounds recorded in electrospray mode, signals of protonated and cationised molecules were observed [M+H] + , [M+NH 4 ] + , [M+Na] + , [M+K] + . Using quantum chemical methods, the models of the obtained compounds were constructed along with a calculation of the formation energies and dissociation constants. Optimisation of the geometric parameters of the equilibrium states of sodium oxoenolate and metal complexes was carried out using the following two methods: density functional theory (DFT) and self-consistent field (SCF). The relative formation energies indicate high stability of the synthesised substances, while, according to the data obtained, copper complexes are characterised by greater stability in the gas phase as compared to zinc and nickel.

Basic properties evaluation of alkyl palmitate to be used as oil insulation

This paper discusses the evaluation of alkyl palmitate to be used as the oil insulation in an oil-filled transformer. Three kinds of alkyl palmitates, namely, Methyl-, Ethyl-, and Isopropyl-palmitates, were prepared through the esterification of methyl-, ethyl-, and iso-propyl-alcohols, respectively, and palmitate acid. The resulted alkyl palmitates were then evaluated for their basic properties such as breakdown voltage, viscosity, density, acidity, and water content based on the ASTM D 6871 standard specification. The peroxide value of the alkyl palmitates was also examined to indicate their oxidation stability and compared the result with that of mineral oil. The results show that viscosity, water content, and density of all alkyl palmitates fulfill the values specified by the standard, whereas, the breakdown voltage and acidity do not. The peroxide value of all alkyl palmitates is still much higher than that of mineral oil.

Biomass‐Derived Aromatics by Solid Acid‐Catalyzed Aldol Condensation of Alkyl Methyl Ketones

AbstractCyclotrimerization of biomass‐based alkyl methyl ketones exhibits great potential as a route to biomass‐derived aromatics by a sustainable valorization of biorefinery streams. In this study, acetone is used as a model reagent to screen solid acid catalysts for the aldol condensation reaction to the aromatic trimer mesitylene. From a broad catalyst screening promising activity is shown by the cation exchange resin Purolite CT275DR, the beta‐zeolite H‐BEA 35, and aluminosilicate Siralox 70/170 HPV which are used to further investigate reaction parameters. Acetone conversion and mesitylene yield increase with temperature and time, while yield of the intermediate mesityl oxide decreases. This effect is also found for higher quantities of catalyst acid sites and is accompanied with an increased side product formation which negatively affects total product selectivity. Analyzing the reaction progress shows a significant drop in catalyst productivity after an initial start‐up phase. This observation is linked to a deactivation of the catalyst which involves water that is formed during the condensation reaction of acetone. Obtained results confirm the general viability of the aromatization of alkyl methyl ketones and can be considered the first step to an alternative sustainable route to biomass‐derived aromatics compared to other currently discussed routes.

Fatty acid alkyl ester nanowebs suitable for renewable thermal energy storage

Owing to their high heat absorption and release capacities, chemical and thermal stability, non-toxicity, two fatty acid alkyl esters (FAAEs), methyl palmitate (MP) and isopropyl palmitate (IPP), were investigated for their use as thermal energy storage (TES) material in a shape stabilized form. Four nanowebs were developed via coaxial electrospinning, using poly(acrylo nitrile) (PAN) or poly(methacrylic acid-co-ethyl acrylate) (PMEA) shell to envelope MP or IPP core. Scanning electron microscope (SEM), transmission electron microscope (TEM) images confirmed cylindrical nanofiber formation, demonstrating a coaxial sheath-core morphology. The phase change enthalpies of PAN-MP, PMEA-MP nanowebs, with average diameters of 259–289 nm, were 71 J g−1 and 86 J g−1 at 28–32 °C, and those of PAN-IPP, PMAE-IPP were 72 J g−1 and 60 J g−1 at 7–15 °C during heating cycle in differential scanning calorimeter (DSC) analyses. A composite including PAN-MP nanoweb performed enhanced thermo-physical properties than its control counterpart.