Benzyltriethylammonium Chloride Research Articles

Emulsion electrospinning of polycaprolactone: influence of surfactant type towards the scaffold properties

Producing uniform nanofibers in high quality by electrospinning remains a huge challenge, especially using low concentrated polymer solutions. However, emulsion electrospinning assists to produce nanofibers from less concentrated polymer solutions compared to the traditional electrospinning process. The influence of individual surfactants towards the morphology of the emulsion electrospun poly (ɛ-caprolactone)/bovine serum albumin (PCL/BSA) nanofibers were investigated by using (i) non-ionic surfactant sorbitane monooleate (Span80); (ii) anionic sodium dodecyl sulfate (SDS); and (iii) cationic benzyltriethylammonium chloride, and poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) triblock copolymer Pluronic F108 of different concentrations. The morphology, along with the chemical and mechanical properties of the fibers, was evaluated by field emission scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, differential scanning calorimetry, water contact angle, and tensile tester. With the addition of surfactants, the electrospinnability of dilute PCL solution was enhanced, with either branched or uniform fibers were obtained. Electrospinning of an emulsion containing 0.4% (w/v) SDS produced the smallest and the most uniform nanofibers (167 ± 39 nm), which was attributed to the high conductivity of the solution. Analysis revealed that the emulsion electrospun nanofibers containing different surfactants and surfactant concentrations differ in fiber morphology and mechanical properties. Results suggest that surfactants have the ability to modulate the fiber morphology via electrostatic and hydrogen bonding, depending on their chemical structure.

Synthesis of a new bis(perfluoroalkyl oxirane) dioxyethylene ether

Classic direct synthetic methods failed to transform bis(perfluororalkylallyl) dioxyethylene ether into the corresponding bis(perfluoroalkyl oxirane). This transformation was instead realized using a mixture of mercuric acetate/bromine to produce the corresponding bromoacetate, which was subsequently transformed to a bromohydrin and further to bis(perfluoroalkyl oxirane) through the use of triethylbenzyl ammonium chloride as a phase transfer catalyst in alkaline media.

ChemInform Abstract: Ring Transformation of (4‐Chloro‐5H‐1,2,3‐dithiazol‐5‐ylidene)acetonitriles to 3‐Haloisothiazole‐5‐carbonitriles.

AbstractThe title transformation can be mediated by gaseous HBr or HCl, and by triethylbenzylammonium chloride.

Residual charge and filtration efficiency of polycarbonate fibrous membranes prepared by electrospinning

ABSTRACTPolycarbonate (PC) ultrafine fiber membranes with benzyl triethylammonium chloride (BTEAC) were prepared by electrospinning of PC/chloroform solution with different BTEAC contents. In the presence of BTEAC additive, the PC solution showed a better electrospinnability and led to thinner fibers with uniformity than the neat PC solution. The charge retention of the electrospun PC fibrous membranes with BTEAC was investigated in terms of additive content, membrane thickness and storage condition. The residual charge on the PC fibrous membrane was increased to 1 wt % BTEAC content, but thereafter gradually decreased up to 10 wt % BTEAC. In addition, the residual charge on the membrane was increased with increasing the membrane thickness, but was rapidly decreased at a high humidity condition in comparison with a low humidity. The filtration efficiency was examined for the fibrous membranes with or without BTEAC. The PC membrane with BTEAC had higher filtration efficiency than one without BTEAC, not affecting the pressure drop. The filtration efficiency between the PC membranes with or without residual charge was also compared. When the residual charge existed on the membrane, the membrane showed higher filter efficiency because of the enhanced filtration effect by an electrostatic attraction. Therefore, the PC fibrous membranes with BTEAC have a great potential as an electrets filter for air filtration. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41340.

Method transfer from high-pressure liquid chromatography to ultra-high-pressure liquid chromatography. I. A thermodynamic perspective

This is the first investigation in a series that aims to enhance the scientific knowledge needed for reliable analytical method transfer between HPLC and UHPLC using the quality by design (QbD) framework. Here, we investigated the differences and similarities from a thermodynamic point of view between RP-LC separations conducted with 3.5μm (HPLC) and 1.7μm (UHPLC) C18 particles. Three different model solutes and one pharmaceutical compound were used: the uncharged cycloheptanone, the cationic benzyltriethylammonium chloride, the anionic sodium 2-naphatlene sulfonate and the pharmaceutical compound omeprazole, which was anionic at the studied pH. Adsorption data were determined for the four solutes at varying fractions of organic modifier and in gradient elution in both the HPLC and UHPLC system, respectively. From the adsorption data, the adsorption energy distribution of each compound was calculated and the adsorption isotherm model was estimated. We found that the adsorption energy distribution was similar, with only minor differences in degree of homogeneity, for HPLC and UHPLC stationary phases. The adsorption isotherm model did not change between HPLC and UHPLC, but the parameter values changed considerably especially for the ionic compounds. The dependence of the organic modifier followed the same trend in HPLC as in UHPLC. These results indicates that the adsorption mechanism of a solute is the same on HPLC and UHPLC stationary phases which simplifies design of a single analytical method applicable to both HPLC and UHPLC conditions within the QbD framework.

Phase Transfer Catalysis: Oxidation of 2-Methyl-1-butanol

In liquid–liquid systems, the substrates in the liquids are inaccessible to each other for the reaction. By adding a small quantity of phase transfer catalyst, the reaction can be made accessible and accelerated. The present study involves the phase transfer catalyzed oxidation of 2-methyl-1-butanol by quaternary ammonium permanganate (tricaprylyl methyl ammonium permanganate). The attempt was to compare the kinetics under homogeneous and heterogeneous conditions. Experiments were conducted in a batch reactor to determine the kinetics under homogeneous conditions. A baffled borosilicate agitated reactor was used to find the enhancement factor and the kinetics under heterogeneous conditions. The rate constants determined under both homogeneous and heterogeneous conditions agreed very well. The oxidation was found to be first order with respect to each of the reactants, quaternary ammonium permanganate and the alcohol, resulting in an overall second order rate expression. Aliquat336 (tricaprylylmethylammonium chloride) was found to be the best compared with the other catalysts tested (triethylbenzylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide and tetrabutylammonium hydrogen sulfate) and it gave an enhancement factor of 9.8.

Chemical Modification of Polyglycidyl Phenol-Formaldehyde Oligomers by Methacrylic Acid

A new oligomer with unsaturated double bonds in the side chains has been synthesized via chemical modification of polyglycidyl phenol-formaldehyde oligomer (PGPFO) by methacrylic acid (MA) using benzyltriethylammonium chloride as a catalyst. The effect of temperature and reaction time on the reaction proceeded between PGPFO and MA has been studied. The effective rate constants and activation energy of the reaction have been calculated. The structure of the synthesized oligomer has been confirmed by chemical and IR-spectroscopic analyses. The cross-linking of epoxy- oligomeric mixtures based on ED-20 epoxy resin, peroxy derivative of epoxy resin, TGM-3 oligoesteracrylate and synthesized oligomer has been examined using polyethylenepolyamine as a hardener.

Tara tannins as phenolic precursors of thermosetting epoxy resins

Tara pods powder was used as a phenolic source in the synthesis of thermosetting epoxy polymer. The tannase-assisted hydrolysis of galloylquinic acids contained in tara powder allowed the determination of the tannins hydroxyl value (13.7mmol/g powder). Then, galloylquinic acids were reacted with epichlorohydrin and an aqueous solution of sodium hydroxide in the presence of benzyltriethylammonium chloride as phase transfer catalyst (PTC). The 1D and 2D NMR analyses of glycidylated products revealed the galloylquinic esters hydrolysis and the dimerisation of the glycidylated gallic moities. The glycidylated derivatives of tara tannins (GETT) were cured in epoxy polymer with isophorone diamine (IPD). The glass transition temperature (Tg=129°C) and the thermal resistance (Td30=294°C) of the resulting network were determined. Preliminary results showed that this new epoxy polymer based on GETT displayed interesting properties which are close to those of the epoxy polymer formulated with commercial diglycidyl ether of bisphenol A (DGEBA).

Radiation synthesis and characterization of styrene/acrylic acid/organophilic montmorillonite hybrid nanocomposite for sorption of dyes from aqueous solutions

Organophilic montmorillonite (OMMT) was synthesized by cationic exchange reaction of Na+‐MMT and vinyl benzyl triethyl ammonium chloride (VBTAC) as a reactive organic modifier in an aqueous solution. A series of styrene (St)/acrylic acid (AA)/OMMT nanocomposite hydrogel containing different wt% of OMMT was synthesized through in situ polymerization using γ‐ray. The samples were characterized using Fourier transform infrared (FTIR), X‐ray powder diffraction (XRD), and transmission electron microscope (TEM), whereas thermal stability was examined by thermogravimetric analysis (TGA). The adsorption capacity and rate for both Acid Green B (anionic) and Maxilon C.I. Basic (cationic) dye including adsorption kinetics and isotherm were investigated at 30°C. TEM measurements showed spherical nanosized particles of average diameter 30–40 nm and XRD suggested the formation of exfoliated nanocomposite. TGA measurements showed that the addition of OMMT did not enhance the thermal stability where the onset temperature of the degradation for all samples was around 125°C. The effect of some important parameters on dye adsorption such as solution pH, initial dye concentration, and contact time was investigated. The equilibrium data obtained in batch experiments were correlated to Langmuir and Freundlich isotherm equations. Results showed that the adsorption of Acid Green B fitted well to the Langmuir model while the adsorption pattern of Maxilon C.I. Basic followed the Freundlich isotherm, which suggests heterogeneity of the adsorption sites on the nanocomposite. POLYM. COMPOS., 35:2353–2364, 2014. © 2014 Society of Plastics Engineers

Inhibiting Action of Quaternary Ammonium Salts on the Corrosion Behaviour of Za-27 Alloy in 1m Na2so4

The inhibition of the corrosion of ZA-27 in 1M Na2SO4 by Quaternary ammoniu salts Benzyl tri methyl ammonium chloride(BTMAC) and Benzyl tri ethyl ammonium chloride(BTEAC) has been investigated using weight loss, potentiodynamic polarization. Results obtained in weight loss studies show that these investigated compounds are good inhibitors and their inhibition efficiencies (IE %) increase with the increase of inhibitor concentration, whereas decreases with increase in immersion time and temperature. Potentiodynamic polarization studies demonstrate the inhibitors under investigation act as mixed type inhibitors and inhibitors changes the mechanism of hydrogen evolution. Effect of temperature is studied between 303 and 333 K differing by 10K. The mechanism of adsorption had been explained on the basis of chemical structure of the investigated inhibitors. It was found that there is a good agreement between the different tested techniques.

O-alkylation of disodium salt of diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate with 1,2-dichloroethane catalyzed by ionic type phase transfer catalyst and potassium iodide

Diethyl 3,4-ethylenedioxythiophene-2,5-dicarboxylate was efficiently synthesized via the O-alkylation of disodium salt of diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate with 1,2-dichloroethane over ionic type phase transfer catalysts, such as tetrabutyl ammonium bromide and benzyltriethyl ammonium chloride. The ionic type phase transfer catalysts showed higher catalytic activities than the nonionic type phase transfer catalysts, such as triethylamine, pyridine, 18-crown-6, and polyethylene glycol 400/600, in the O-alkylation reaction. The conversion of the disodium salt of more than 97% and the selectivity of diethyl 3,4-ethylenedioxythiophene-2,5-dicarboxylate of more than 98% were achieved when the O-alkylation reaction was synergistically catalyzed by tetrabutyl ammonium bromide and potassium iodide.

Immobilization of Candida rugosa lipase on bentonite modified with benzyltriethylammonium chloride

Two organobentonites with different hydrophobicities were used as supports for the immobilization of Candida rugosa lipase (CRL). The activities of the free and immobilized lipases were evaluated for the hydrolysis of olive oil. The organobentonites were prepared from sodium bentonite by interchange with benzyltriethylammonium chloride, using 1.0 and 2.1 times the cation exchange capacity (CEC) of the clay. The enzymatic activities of the lipase immobilized in the two organobentonites were 511.5 and 177.8 U/g support, while the activity recoveries were 33.5% and 14.7%. The operational stability of the immobilized enzyme as a function of pH and temperature was analyzed, and the resulting data were processed using analysis of variance (ANOVA) and response surface methodology (RSM). The conditions where the highest retention of activity for the CRL immobilized in the organobentonite using 1.0 times the CEC was found to be at a pH of 6.5 and a temperature of 39.6 °C. For the CRL immobilized in the organobentonite with 2.1 times the CEC, an ideal temperature was not found in the range evaluated and the optimal pH was determined to be 6.5. In general, the immobilization process preserved the enzyme structure in the interval of pH (5.5–7.0) and temperature (35–45 °C) studied and opens a broad range of possible industrial applications.

O-Arylation of Iodophenols with 2-Fluorobenzaldehyde Under Microwave Conditions

The arylation of 4-iodo-, 2-iodo- and 3-iodophenols with 2-fluorobenzaldehyde may be carried out in the presence of K2CO3 in DMF as the solvent under microwave conditions. The arylation of 4-iodophenole was promoted by the use of triethylbenzylammonium chloride (TEBAC) as the phase transfer catalyst. In the other model reactions, the use of TEBAC was harmful. By-products formed by isomerization and disproportionation were also detected.

Triethyl benzyl ammonium chloride (TEBAC) catalyzed solvent-free one-pot synthesis of pyrimido[4,5-d]pyrimidines

A series of pyrimido[4,5-d]pyrimidine derivatives were synthesized by a multicomponent reaction of urea/thiourea, aldehyde and barbituric or thiobarbituric acid in the presence of triethyl benzyl ammonium chloride as a catalyst under solvent-free conditions. The pure products were obtained after recrystallization from ethanol. All synthesized compounds were characterized using IR and NMR (1H and 13C) spectroscopic and elemental analyses data.

The Benzoin Condensation Reaction in the Presence of the Ultrasonic

This text will lead to a new phase transfer catalyst ultrasonic reaction and affected the condition of benzoic condensation reaction. From this research we found that when the reaction temperature is 60-65 °C, pH is 9.5, ultrasonic time is 70 minutes, benzyltriethylammonium chloride is 0.45g, and the benzoin yield is 68.9%.

Solvent influence on formation of C—H...π interactions in benzyltriethylammonium chloride withrac-1,1′-binaphthol

Solvent influence on formation of C—H...π interactions in benzyltriethylammonium chloride with<i>rac</i>-1,1′-binaphthol

Bismuth complex catalysts for the in situ preparation of polycaprolactone/silicate bionanocomposites

Solvent-free, bismuth-catalysed in situ polymerization of caprolactone in the presence of layered silicates enables the formulation of a series of polycaprolactone/silicate bionanocomposites. Three organophilic montmorillonites obtained by cationic exchange reaction with tetrabutylammonium iodide, benzyltriethylammonium chloride and vinylbenzyltriphenylphosphonium chloride salts, respectively, were used as reinforcing reagents for these materials. The effects of clay and bismuth catalyst type (bismuth(III) acetate and triphenylbismuth) are discussed on the basis of composite morphologies and molecular weights of resulting polymers. © 2013 Society of Chemical Industry

Investigation on the Acylation of Heterocyclic Alcoholate Anions with O,O-Dialkyl Phosphorochloridothioate in Water Solvent

The acylation of some heterocyclic alcoholate anions with O,O-dialkyl phosphorochloridothioate has been investigated. Higher yields and fewer byproducts were achieved in water at 50 °C by employing an effective phase-transfer catalyst (PTC) (benzyl triethylammonium chloride [BTEAC]), acylation catalyst (AC) (4-dimethylaminopyridine), and surfactant (sodium dodecyl sulfate), under weakly basic (pH 9.5∼10) conditions. This reaction can also be applied to synthesize other insecticides with excellent yields.

ChemInform Abstract: An Efficient Synthesis of N‐Substituted‐3‐aryl‐3‐ (4‐hydroxy‐6‐methyl‐2‐oxo‐2H‐pyran‐3‐yl)propanamides by Four‐Component Reaction in Aqueous Medium.

A mild and efficient synthesis of N-substituted-3-aryl-3-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)propanamides via four-component reaction of an aldehyde, amine, Meldrum's acid, and 4-hydroxy-6-methyl-2H-pyran-2-one in the presence of benzyltriethylammonium chloride (TEBAC) in aqueous medium is described. This method has the advantages of accessible starting materials, good yields, mild reaction conditions, and begin environmentally friendly.

Propargylation of arabinogalactan with propargyl halides—a facile route to new functionalized biopolymers

New arabinogalactan propargyl ethers with degree of substitution (DS) up to 2.8 have been obtained by propargylation of arabino-3,6-galactan (AG) with propargyl bromide (PB) in the two-phase system 30–60% КОН aqueous solution/toluene in the presence of triethylbenzylammonium chloride (TEBAС) or without catalyst (ambient temperature, 1–24h) in 20–87% yields. The highest yields have been reached using TEBAС as phase-transfer catalyst, though the non-catalytic version proves to be also efficient (DS 2.8, 70% yield). The propargylation of AG is less effective in the systems MОН (M=Na, K)/DMSO. DS of propargyl AG reaches 1.8 (70% yield) when propargyl chloride is used as propargylating agent, while with PB under the same conditions DS value does not exceed 0.4–0.6, the yields being 44–65%. Under the action of t-BuOK/DMSO system, the AG propargyl ethers have been isomerized to the corresponding unstable allenyl ethers. AG propargyl ethers with DS 2.0 have been almost exhaustively metallated with Ag2O/NH3 system to give AG–Ag acetylides derivatives with Ag/CC ratio equaling 0.95.