Benzyltriethylammonium Chloride Research Articles

Synthesis and characterization of poly(methylene disulfide) and poly(ethylene disulfide) polymers in the presence of a phase transfer catalyst

Poly(methylene disulfide) and poly(ethylene disulfide) were synthesized from the polycondensation of methylene dichloride and ethylene dichloride monomers, respectively, in the presence of benzyltriethylammonium chloride as a phase transfer catalyst. The structures of the synthesized polysulfides were confirmed via the elemental analysis, attenuated total reflectance Fourier transform infrared spectroscopy and X-ray diffraction techniques. Moreover, the thermal behaviors of synthesized poly(methylene disulfide) and poly(ethylene disulfide) were characterized using differential scanning calorimetry and thermogravimetric analysis methods. The synthesized poly(methylene disulfide) and poly(ethylene disulfide) have molecular weights of about 2262 and 2863 g/mol, respectively. In addition, the polymers have crystalline structures absorbed in the amorphous sections. However, the d-spacing of polymers’ crystalline parts was different. Moreover, poly(methylene disulfide) and poly(ethylene disulfide) have a two- and one-step degradation behavior, respectively.

Microwave-Assisted Solid-Liquid Phase Alkylation of Naphthols

The microwave promoted alkylation of 1- and 2-naphthols with benzyl, butyl, ethyl and isopropyl halides in the presence of an alkali carbonate may result in O- and C-alkylated products. The alkylations were O-selective in the presence of K2CO3 in acetonitrile as the solvent and in the absence of phase transfer catalyst. The alkylations utilizing butyl and ethyl halides were also O-selective in solventless accomplishment and in the presence of triethylbenzylammonium chloride. Keywords: O-alkylation, C-alkylation, microwave, phase transfer catalyst.

Synthesis of branched cores by poly-O-alkylation reaction under phase transfer conditions. A systematic study

In the present paper is described a systematic study of poly-O-alkylation reactions of pentaerythritol (PE) and 1,1,1-tris(hydroxymethyl)ethane (TME) by 1,4 Michael addition, under phase transfer catalysis (PTC), considering the effect of: (1) the organophilicity of PTC (three different catalysts were tested), (2) PTC concentration (from catalytic to equimolar conditions), and (3) the regime of addition of reactants coexisting in the aqueous phase of the heterogeneous reaction system. The less organophilic transfer agent showed the best performance on these reactions. In our case, benzyltriethylammonium chloride (TEBAC) gathers the best features. The presence of NaOH as base, promotes the interfacial mechanism and not the bulk one. Out of the optimal range of concentration of NaOH (35–40%), competition between nucleophiles can occur, due to the saturation of the medium. Regarding the regime of addition of reactants, the scenario where NaOH and TEBAC are less time in contact, favors the formation of the desired products. Finally, the deprotection of tert-butyl groups of the poly-O-alkylated compounds is described, to get branched cores with terminal carboxylic acid groups in good yields (90–94%). Spectroscopic properties, such as IR, 1H and 13C NMR, of the synthesized compounds are also described.

Preparation and Characterization of Diiodocarbene Functionalized Multi-walled Carbon Nanotubes

The addition of diiodocarbene to Multi-walled carbon nanotubes was investigated. Using iodoform as precursor and benzyltriethylammonium chloride (BZTMAC) as the phase transfer catalyst, the degree of diiodocarbene functionalization was around 29.4 wt%. High-resolution transmission electron microscopy (HR-TEM) images showed that the morphology of the nanotubes was found to be largely intact after functionalization. The functionalized carbon nanotubes were fully characterized using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Fourier transform infrared (FT-IR) spectroscopy. The band gap energy values for pristine multiwalled carbon nanotubes and the functionalized multi-walled carbon nanotubes were measured and calculated. Keywords: Diiodocarbene, multi-walled carbon nanotubes, functionalization, characterization

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.

Influence of antimicrobial additives on the formation of rosin nanofibers via electrospinning

In this study, we describe the influence of antimicrobial additives on the formation of rosin fibers by using electrospinning technique. Systematic experiments were performed to fabricate the rosin fibers via electrospinning and we tried to reduce the size of the fibers by mixing some additives such as triethylbenzylammonium chloride (TEBAC), chitosan and silver nitrate in the rosin polymer solution. The morphology, structure and thermal properties of the electrospun rosin fibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet–visible spectroscopy and thermogravimetry (TGA). Rosin fibers with a diameter of the order of nanoscale were achieved by the use of TEBAC additive. The antimicrobial activity of the resultant fibers was checked by the antimicrobial disc diffusion test. All the rosin fibers showed excellent antibacterial activity against the gram negative bacteria and feeble activity against the gram positive bacteria. The present study demonstrated that the electrospun rosin fibers can be utilized for potential antimicrobial products.

Synthesis of new copolymers 4,4’-sulfinylbisphenol derivative with N-vinyl-2-pyrrolidone - photopolymerization and thermo-mechanical studies

AbstractSynthesis, structure and characterization of the new sulfur monomer sulfinylbis[benzene-4,1-diyl(oxy-2-hydroxypropane-3,1-diylmethacrylate)] (SO.DM) and its photopolymerization with N-vinyl-2-pyrrolidone (NVP) are presented. SO.DM was obtained in the three-step reaction. In the first step, 4,4’- sulfinylbisphenol from 4-[(4-hydroxyphenyl)thio]phenol was obtained. In the second step the epoxy compound was synthesized. It was obtained in the reaction of 4,4’- sulfinylbisphenol with 2-(chloromethyl)oxirane in the two phases liquid/liquid system including organic and aqueous phases. In the third step, ring opening of the obtained diglycidyl ether was carried out with the use of methacrylic acid in the presence of triethylbenzylammonium chloride (TEBAC) as a catalyst. Structures of new compounds were confirmed by spectroscopic methods (FT-IR, 1H and 13CNMR and DIP-MS). Photopolymerization of compositions containing different ratios of the monomers (SO.DM and NVP) and an initiator (Irgacure 651) was carried out. The following properties (before and after curing) were determined: density, polymerization shrinkage, glass transition temperature, Young’s modulus, hardness, tensile strength. Moreover, dynamic-mechanical and thermal properties were studied.

Study of the O-glycidylation of natural phenolic compounds. The relationship between the phenolic structure and the reaction mechanism

The O-alkylation reaction by epichlorohydrin of some natural phenolic compounds such as 4-methylcatechol, gallic acid, protocatechuic acid, pyrogallol and resorcinol was investigated. Phenolic compounds reacted first with epichlorohydrin in the presence of benzyltriethylammonium chloride as phase transfer catalyst. Then, an aqueous solution of sodium hydroxide was added.It was demonstrated that the two competitive mechanisms involved in the O-alkylation reaction were highly dependent of the starting material. The O-alkylated products obtained in this reaction could be further used as bisphenol A substitutes in the synthesis of epoxy resins pre-polymers.

An Expedient Phase Transfer Catalyst‐Mediated Synthesis of 2‐Alkyl/Aryl‐1,8‐phenanthrolines

Several 2‐alkyl and 2‐aryl‐1,8‐phenanthrolines were synthesized efficiently from 5‐aminoisoquinoline and seven α,β‐unsaturated aldehydes in aq. HCl–toluene mixture at 100°C using benzyltriethylammonium chloride as a phase transfer catalyst.

ChemInform Abstract: Effective Synthesis of tert‐Butyl‐Substituted 3‐Carboxy Coumarins in Water Using TEBAC as Catalyst.

AbstractHitherto unreported hydrophobically substituted 3‐carboxycoumarin derivatives (III) are synthesized by modifying a known method through use of benzyltriethylammonium chloride as catalyst.

Synthesis and characterization of poly(p-xylylene tetrasulfide) via interfacial polycondensation in the presence of phase transfer catalysts

Poly(p-xylylene tetrasulfide) was synthesized from 1,4-bis(chloromethyl)-benzene and sodium tetrasulfide using interfacial polycondensation technique to examine the effect of methyl tributyl ammonium chloride, tetrabutyl ammonium bromide, and benzyl triethyl ammonium chloride as phase transfer catalysts. The structure of the synthesized polysulfide was confirmed via elemental analysis, attenuated total reflectance Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction techniques. Moreover, the thermal behavior of this polymer was characterized using differential scanning calorimetry and thermo gravimetric analysis methods. Beyond, Friedman method was applied to analyze the degradation kinetics of the prepared polymer. The synthesized polymer had a molecular weight of about 2584 g/mol.

Effective Synthesis of tert-Butyl-Substituted 3-Carboxy Coumarins in Water Using TEBAC as Catalyst

A facile synthesis of novel tert-butyl substituted 3-carboxycoumarin derivatives is described, featuring the one-pot reaction of tert-butyl substituted salicylaldehydes with Meldrum's acid in water using triethylbenzyl ammonium chloride (TEBAC) as catalyst.

Characterization of synthesized poly(aryldisulfide) through interfacial polymerization using phase-transfer catalyst

A new polysulfide polymer was synthesized from 1,4-bis(chloromethyl)-benzene and sodium disulfide by an interfacial polycondensation technique in the presence of tetrabutyl ammonium bromide, methyltributyl ammonium chloride and benzyl triethyl ammonium chloride as phase-transfer catalysts (PTC). The effect of PTC on the kinetics of polymerization was investigated. Structures of this aromatic polysulfide were confirmed through elemental analyses, attenuated total reflectance Fourier transform infrared spectroscopy, Raman spectroscopy, an X-ray diffraction technique, and a nuclear magnetic resonance spectroscopy method. The thermal behavior of this polymer was also characterized by differential scanning calorimetry and thermogravimetric analysis. The solubility of prepared polymer was critically dependent on the identity of the solvent.

Effect of benzyl triethylammonium chloride on microstructure of bicomponent polymeric fibers during electrospinning

AbstractEffect of benzyl triethylammonium chloride (BTEAC) on the microstructure of electrospun bicomponent fibers, i.e., polyvinylidene fluoride (PVDF)/polycarbonate (PC), polyacrylonitrile (PAN)/polyethylene glycol (PEG), and PAN/PVDF, was investigated in this article. The evolution of morphology and microstructure of the above bicomponent fibers were examined by scanning electron microscopy, transmission electron microscopy, and X‐ray photoelectron spectroscopy. The results showed that distinct core/shell structured fibers were successfully prepared from PVDF/PC and PAN/PVDF via introducing a small amount of BTEAC, whereas only cocontinuous structure was detected in the electrospun PAN/PEG fibers. This study could be an example of electrospun multipolymer dispersions influencing by an organic salt, and it could be extended to control the structure of carbon nanofibers via electrospinning. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers

Degradation of electrospun poly(L‐lactide) membranes under cyclic loading

AbstractBecause of the great effect of mechanical loads on degradation of biodegradable biomaterials, investigation on degradation of electrospun membranes under dynamic loading is of importance. In this article, degradation of electrospun poly(L‐lactide) (PLLA) membranes was carried out in a Tris‐HCl buffer solution containing proteinase K under a cyclic stretch loading (dynamic condition) in comparison with that in shaking water bath (static condition). The evolutions of mass loss, morphology, thermal properties, and relative molecular weight of PLLA were monitored during degradation. The results showed that after degradation for 10 h, the mass of the electrospun PLLA membranes dropped by 38.7% and 31.3%, respectively, under dynamic and static conditions. And the electrospun PLLA membranes showed higher value of crystallinity during degradation under both cyclic loading and static condition. In addition, benzyl triethyl ammonium chloride (BTEAC) was introduced during electrospinning, and the effects of electrospun membranes characteristic and crystallinity on degradation were also investigated. The degradation study results are expected to be a basic study in mimicking actually mechanical environments. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci 124:258–266, 2012

Synthesis and in vitro Antibacterial Activities of 5‐(2,3,4,5‐Tetrahydro‐1H‐chromeno[2,3‐d]pyrimidin‐5‐yl)pyrimidione Derivatives

AbstractA series of novel 5‐(2,3,4,5‐tetrahydro‐1H‐chromeno[2,3‐d]pyrimidin‐5‐yl)pyrimidione derivatives have been synthesized from substituted salicylaldehydes and barbituric acid or 2‐thiobarbituric acid in water catalyzed by phase transfer catalysis of triethylbenzyl ammonium chloride (TEBA). Elemental analysis, IR, 1H NMR, and 13C NMR elucidated the structures of all the newly synthesized compounds. In vitro antimicrobial activities of synthesized compounds have been investigated against Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa. These newly synthesized derivatives exhibited significant in vitro antibacterial activity.

An Efficient Synthesis of N‐Substituted‐3‐aryl‐3‐(2‐hydroxy‐4,4‐dimethyl‐6‐oxocyclohex‐1‐enyl)propanamides by Four‐component Reaction in Aqueous Medium

AbstractA mild and efficient synthesis of N‐substituted‐3‐aryl‐3‐(2‐hydroxy‐4,4‐dimethyl‐6‐oxocyclohex‐1‐enyl)propanamides via four‐component reaction of an aldehyde, amine, Meldrum's acid and 5,5‐dimethylcyclo‐hexane‐1,3‐dione 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 eco‐friendliness.

Electrospinning and cutting of ultrafine bioerodible poly(lactide‐co‐ethylene oxide) tri‐ and multiblock copolymer fibers for inhalation applications

AbstractTriblock copolymers made up of poly(ethylene oxide) (PEO) and polylactide (PLA) were synthesized and converted to fibers by the electrospinning process. A two‐step in situ‐synthesis in bulk was applied to extend PLA‐PEO‐PLA triblock copolymers with relatively short block length and low molecular weight in order to obtain electrospinnable materials. DL‐lactide was polymerized to the hydroxyl chain ends of PEO via the stannous octoate route. Hexamethylene diisocyanate (HDI) was added as chain extender in the second step, leading to poly(ether‐ester‐urethane) multiblock copolymers. The materials were electrospun from solutions in chloroform. Different concentrations and voltages were analyzed. The ether and ester blocks were varied in their block length and their effects on the fiber morphology was studied. Variations in the electrical conductivity of the chloroform solutions were investigated by adding triethyl benzyl ammonium chloride (TEBAC) in different amounts. Finally, with high quality electrospun PLA‐PEO‐PEO triblock copolymer fibers mechanical cutting was possible. Copyright © 2009 John Wiley & Sons, Ltd.

Synthesis and exploration of QSAR model of 2-methyl-3-[2-(2-methylprop-1-en-1-yl)-1H-benzimidazol-1-yl]pyrimido[1,2-a]benzimidazol-4(3H)-one as potential antibacterial agents

Present communication deals with the synthesis of novel 2-methyl-3-[2-(2-methylprop-1-en-1-yl)-1H-benzimidazol-1-yl]pyrimido[1,2-a]benzimidazol-4(3H)-one derivatives under phase transfer catalysis (PTC) conditions using benzyl triethyl ammonium chloride (BTEAC) as PTC. It also elicits the studies on in vitro antimicrobial evaluation of synthesized compounds against a representative genera of gram-negative and gram-positive bacteria i.e., Bacillus subtilis, Staphylococcus aureus, Pseudomonas diminuta and Escherichia coli. All the compounds have been found to manifest profound antimicrobial activity. Moreover, extensive quantitative structure-activity relationship (QSAR) studies have been performed to deduce a correlation between molecular descriptors under consideration and the elicited biological activity. A tri-parametric QSAR model has been generated upon rigorous statistical treatment.

Structure and properties of electrospun poly(vinylidene fluoride)/polycarbonate membranes after hot‐press

AbstractPoly(vinylidene fluoride) (PVDF)/polycarbonate (PC) dispersed solutions were electrospun into ultrafine core/shell fibers and modified by hot‐press. Morphology, tensile properties, porosity, and liquid absorption of the electrospun membranes as well as the crystallinity of PVDF were examined before and after hot‐press. Results showed that the tensile strength and tensile modulus of the electrospun membranes increased after hot‐press, especially when poly(methyl methacrylate) (PMMA) or benzyl triethylammonium chloride (BTEAC) was introduced for the formation of distinct core/shell fiber structure. The elongation of the hot‐pressed electrospun PVDF/PC membrane with addition of BTEAC was also significantly enhanced by reason of the clearest core/shell structure. The crystallinity of PVDF did not change too much before and after hot‐press, however the porosity and liquid absorption of the hot‐pressed electrospun membranes decreased to about 58% and around 75–90%, respectively, with no significant differences between PVDF/PC, PVDF/PC/PMMA, and PVDF/PC with BTEAC membranes. This study could be an example of electrospun membranes in multi‐polymer components and it could be extended to other systems of electrospinning for applications in filtration and so on. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011