The example of polyethylene of low density (PELD) crystallization in ethylbenzene and some other alkylbenzenes presence demonstrates
the unsufficiency of formal liquidus curve knowledge for the description of phase equilibrium in amorphous-crystalline polymer-liquid
system. Experimental data affirming polymorphous structure of PELD crystalline phase and influence of the solvent on the order
of various regular structures formation in it are being reported.
Authors:Rakesh Kumar, Anil Kumar, and Ashok Khanna
Linear alkylbenzenes (LABs) are used in the production of the detergents. The formation of the LABs is carried out by the alkylation of benzene with long chain olefins (C 10 –C 14 ), in the presence of AlCl 3 , HF
Authors:Olga Yugay, Tatyana Mikhailovskaya, Lyudmila Saurambaeva, Dauren Sembaev, and Pavel Vorobiov
Titanium dioxide is applied to the preparation of the catalysts used in the oxidation and ammoxidation of alkylbenzenes and alkylpyridines [ 1 ]. A crystal modification of titanium dioxide influences on the
K2PtCl4 was found to be an efficient and very useful homogenous catalyst for deuterium and tritium exchange of the aromatic hydrogens of phenylalanines and phenylglycine. The exchange reactions of the aromatic ring hydrogens, observed in the 80–130°C temperature interval proceed according to an electrophilic substitution mechanisms. The investigated hydrogen exchange processes involve the reversible formation of -complexes with the aromatic ring, analogous to -complexes postulated in deuterium exchange studies with alkylbenzenes. The probable mechanisms of the platinum(II) catalyzed homogeneous deuterium and tritium exchange of aromatic ring hydrogens and of the methoxy and ethoxy para-substituents are discussed.
Authors:B. Marongiu, Alessandra Piras, Silvia Porcedda, and Enrica Tuveri
A flow microcalorimeter has been used to determine excess enthanlpies (HE) at 298.15 K for binary mixtures of dimethylsulfoxide (1)+alkylbenzenes (benzene, methylbenzene, ethylbenzene, n-propylbenzene and sec-propylbenzene, n-butylbenzene, sec-butylbenzene and tert-butylbenzene) or tetrachloromethane, trichloromethane, tetrachloroethane, dichloromethane and monochloroalkanes (1-chloropropane,
1-chlorobutane, 1-chloropentane, 1-chlorohexane) (2). These data with the data available in the literature on the molar excess
enthalpies (HE), molar excess Gibbs energies (GE), activity coefficients at infinite dilution, γi∞, liquid-vapour equilibria (LVE) and liquid-liquid equilibria (LLE) for dimethylsulfoxide (DMSO)+n-alkanes, cyclohexane, benzene or alkylbenzenes (mono-, dialkyl-and trialkyl-) or tetrachloromethane, trichloromethane, dichloromethane
and monochloroalkanes are treated in the framework of DISQUAC, an extended quasi-chemical group contribution theory.
The systems are characterized by three types of contact surfaces: sulfoxide (S=O group), aliphatic (CH3, CH2, CH groups), cycloaliphatic (c-CH2 group), aromatic (C6H6, C6H5 groups) and chlorine (C1 group). Using a set of adjusted contact interchange energies parameters, structure dependent, the
model provides a fairly consistent description of the thermodynamic properties as a function of concentration. The model may
serve to predict missing data.
New polyacrylate-based monosized-porous polymer beads were proposed as a stationary phase for the separation of polar compounds by microbore reversed-phase chromatography. For this purpose, monosized-porous poly(glycerol dimethacrylate-co-glycerol-1,3-diglycerolate diacrylate), poly(GDMA-co-GDGDA), beads with hydroxyl functionality were synthesized by a modified seeded polymerization. The selected octadecylating agent, stearoyl chloride (SC), was covalently attached onto the hydrophilic beads via a direct, single stage reaction with a simple synthetic route. SC attached-poly( GDMA-co-GDGDA) beads were slurry-packed into the microbore columns and used as separation medium microbore reversed-phase chromatography. The stationary phase was used for separation of alkylbenzenes and polar analytes by micro reversed-phase chromatography, using mobile phases with low acetonitrile content. Theoretical plate number (TPN) values up to 12,000 plates m−1 and 10,000 plates m−1 for alkylbenzenes and polar analytes, respectively, were achieved. The results also showed that poly(GDMA-co-GDGDA) hydrogel beads are a promising starting material for a number of chromatographic applications like reversed-phase (RP) chromatography, hydrophilic interaction chromatography (HILIC), ion-exchange chromatography (IEC), and affinity chromatography with a single-stage surface modification.
. Li, J. Chen, Y. Wang,* G. Luo, H. Yu Bioresource Technology 2014 , 169 , 416–420
“Selective synthesis of linear alkylbenzene by alkylation of benzene with 1-dodecene over desilicated zeolites” W. Aslama, M. A. B. Siddiquia
Authors:K. V. Novikova, M. O. Kompanets, O. V. Kushch, S. P. Kobzev, M. M. Khliestov, and I. O. Opeida
The selective oxidation of alkylbenzenes with a green oxidant (molecular dioxygen) to oxygen-containing compounds such as alcohols, ketones and carboxylic acids is a very important industrial process. Traditional