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Toluene Sulfonic Acid (toluene + sulfonic_acid)
Selected AbstractsKinetics and mechanism of myristic acid and isopropyl alcohol esterification reaction with homogeneous and heterogeneous catalystsINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 3 2008Tuncer Yalçinyuva The reaction of myristic acid (MA) and isopropyl alcohol (IPA) was carried out by using both homogeneous and heterogeneous catalysts. For a homogeneously catalyzed system, the experimental data have been interpreted with a second order, using the power-law kinetic model, and a good agreement between the experimental data and the model has been obtained. In this approach, it was assumed that a protonated carboxylic acid is a possible reaction intermediate. After a mathematical model was proposed, reaction rate constants were computed by the Polymath* program. For a heterogeneously catalyzed system, interestingly, no pore diffusion limitation was detected. The influences of initial molar ratios, catalyst loading and type, temperature, and water amount in the feed have been examined, as well as the effects of catalyst size for heterogeneous catalyst systems. Among used catalysts, p -toluene sulfonic acid (p -TSA) gave highest reaction rates. Kinetic parameters such as activation energy and frequency factor were determined from model fitting. Experimental K values were found to be 0.54 and 1.49 at 60°C and 80°C, respectively. Furthermore, activation energy and frequency factor at forward were calculated as 54.2 kJ mol,1 and 1828 L mol,1 s,1, respectively. © 2008 Wiley Periodicals, Inc. 40: 136,144, 2008 [source] Preparation and self-assembly of polyaniline nanorods and their application as electroactive actuatorsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Seong Hun Kim Abstract To improve the performance of ion-exchange polymer,metal composite (IPMC) actuators, an electrical pathway material for enhancing the surface adhesion between the membrane and the metal electrodes of the IPMC was studied. As an efficient electrical pathway material, polyaniline nanorods (PANI-NRs) doped with p -toluene sulfonic acid (TSA) were synthesized with a template-free method. The factors affecting polyaniline morphology were studied with various dopant concentrations and oxidant feeding rates. Highly conductive PANI-NRs were formed when they were synthesized with ammonium persulfate at a 5.0 mL/min oxidant feeding rate and doped with 0.125M TSA. The conductivity of the PANI-NRs was 1.15 × 10,1 S/cm, and their diameters and lengths were 120,180 nm and 0.6,2 ,m, respectively. To apply the membrane as an actuator, perfluorosulfonated ionomer (Nafion)/PANI-NR blends were prepared by solution blending and casting. The actuating ability of the three-layered membrane consisting of Nafion/PANI-NR blends was then examined and compared with that of Nafion only. The actuating ability of the IPMC was improved when Nafion/PANI-NRs were used as electrical pathways. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Kinetics of esterification of palmitic acid with isopropanol using p -toluene sulfonic acid and zinc ethanoate supported over silica gel as catalystsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 10 2004Roomana Aafaqi Abstract Kinetic data on the esterification of palmitic acid with isopropanol were obtained using homogeneous (para -toluene sulfonic acid, p -TSA) and heterogeneous (zinc ethanoate coated on silica gel, ZnA/SG) catalysts in a batch reactor. The ZnA/SG catalyst was prepared using a sol,gel technique. The esterification reaction was studied at different reaction temperatures (373,443 K), initial reactants molar ratio (1,5), catalyst loading (1,5 gcat dm,3) and water concentration in feed (0,15 vol%). A power law rate equation was used for homogeneous kinetics analysis. The Langmuir Hinshelwood Hougen Watson (LHHW) model was used for heterogeneous kinetics. The kinetic parameters of both models were obtained using Polymath software. The reaction parameters were used to obtain simulated values of conversion for both catalytic systems. The simulated values were compared with the experimental values and were in good agreement. Copyright © 2004 Society of Chemical Industry [source] The unidirectional glass fiber reinforced furfuryl alcohol for pultrusion.POLYMER COMPOSITES, Issue 6 2008The development of unidirectional glass fiber reinforced furfuryl alcohol (FA) composites has been conducted using an in situ polymerization method. The FA prepolymer synthesized in this study was prepared from blends of FA monomer and catalyst (p -toluene sulfonic acid). The process feasibility, and kinetic analysis of the unidirectional glass fiber reinforced FA composites by pultrusion has been investigated. From the investigations of the long pot life of FA prepolymer, the high reactivity of FA and FA/glass fiber, and excellent fiber wet-out of FA resin and glass fiber, it was found that the FA resin showed excellent process feasibility for pultrusion. A kinetic autocatalytic model, d,/dt = A exp(,E/RT),m(1,,)n, was proposed to describe the curing behavior of FA/glass fiber composites. Kinetic parameters for the model were obtained from dynamic differential scanning calorimetry scans using a multiple regression technique. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers [source] Bis(trifluoromethyl)phosphinous Acid (CF3)2P-O-H: An Example of a Thermally Stable Phosphinous Acid,Synthesis, Gas-Phase Structure, and Rotational IsomersCHEMISTRY - A EUROPEAN JOURNAL, Issue 13 2006Berthold Hoge Priv.-Doz. Abstract The bis(trifluoromethyl)phosphinous acid, (CF3)2POH, is the only known example of a thermally stable phosphinous acid. Although this compound has been known since 1960, little is known about the chemistry of this extraordinary compound; this might be due to the tedious, and in some part risky, synthesis that was originally published. An improved, simple, and safe synthesis that is based on the treatment of the easily accessible (CF3)2PNEt2, with at least three equivalents of p -toluene sulfonic acid, is presented. The reaction results in a complete conversion to the phosphinous acid, which is isolated in almost 90,% yield. The compound exists in an equilibrium of two POH rotational isomers, a fact which is supported by quantum chemical calculations. The relative enthalpy difference of 6.4 kJ,mol,1, calculated at the B3PW91/6-311G(3d,p) level, is in excellent agreement with the experimental value of 5.9 kJ,mol,1, which was determined from the temperature dependence of the (OH) bands of the two rotational isomers. The complete experimental vibrational spectra of both rotamers, their predicted vibrational spectra obtained by using quantum chemical calculations, and an attempt at photoinduced isomerization of matrix-isolated (CF3)2POH is presented. The experimental structure, obtained from an electron-diffraction study in the gas phase, is reproduced very well by ab initio and density functional theory (DFT) methods. [source] | |||||||||||||