Ion Exchange Catalysis Research Articles

Polymer composites and their properties

The review article summarizes the results of studies conducted in the field of polymer composites obtained by various methods. An important industrial activity is structured around the development of polymeric materials and composites based on them. Composite materials having a matrix comprised of a polymeric material (polymers, oligomers, copolymers) are highly numerous and diverse. They are widely used in the industry for the manufacture of vitreous, ceramic, electrically insulating coatings, as adsorbents in the treatment of wastewater from heavy metal ions, and in the production of ion-exchange membranes. Composite materials have unique properties such as a large surface area, thermal and mechanical stability, good selectivity against various contaminants, and cost-effectiveness. The review presents the physicochemical and structural characteristics of composite materials based on synthetic polymers (polymer-carbon, polymerclay composites), polymeric heterocyclic and organosilicon compounds. Used across a variety of applications, polymer-carbon and polymer-clay composites are effective in removing organic and inorganic contaminants. However, when used as adsorbents for large-scale production, they have yet to achieve optimum performance. Hybrid materials obtained by the sol-gel method deserve special attention. This method can be conveniently used to influence the composition and structure of the surface layer of such materials as adsorbents of heavy and noble metals, catalysts, membranes and sensors for applications in biological antibiosis, ion exchange catalysis, etc. Such composites are characterized by their increased mechanical strength and thermal stability, as well as offering improved thermochemical, rheological, electrical and optical properties.

FEATURES OF PHENOL ALKYLATION WITH HIGHER ALPHA – OLEFINS ON MACROPOROUS SULFOCATIONITES

The features of phenol alkylation by higher alpha-olefins to obtain monoalkylphenols (MAP) using commercial industrial samples of macroporous sulfocationites are considered: Tulsion-66 and Amberlist 36 dry, which are in different price categories and differ significantly in geometric dimensions: pore diameter at Tulsion-66 = 450-500 A; at Amberlist 36 dry =240 A; pore volume (cm3/g) 0.35 and 0.2, respectively. The thermodynamic analysis of a complex mixture of simultaneously occurring reversible reactions of the formation of target monoalkylphenols (the sum of ortho - and para - isomers) and by-products (dialkylphenols and alkylphenyl ether) in the range of 383-408 K was performed. It was found that to obtain 97-98% equilibrium monoalkylphenols yield, it is necessary to have a 4-6 fold molar excess of phenol with respect to olefins. It is not recommended to raise the temperature above 408 K, as this leads to a significant increase in by-products. In the course of kinetic studies, the optimal concentration of sulfocationites was established - 20% for the initial mixture, providing maximum rates for the selected samples under the same conditions while maintaining selectivity for the target monoalkylphenols at the level of 97-98%. Thus, at T=383 K, the phenol/olefin ratio =6: 1, the reaction rate on Tulsion-66 is 1.6-1.7 times higher than on Amberlist 36 dry. The activation energies estimated from experimental data in the studied temperature range had values (kJ/mol) : 14.64±1.89 on Tulsion-66 and 26.53±3.2 on Amberlist 36 dry. Differences in the reactivity of the investigated sulfocationites confirm the known theoretical positions, according to which the reaction rate during ion exchange catalysis depends on the ratio of the sizes of reacting molecules and catalyst pores.

Solvent‐Free Ion Exchange Catalysis in the Oxidation of Organic Compounds with Sodium Bromate.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Ion Exchange Catalysis in Oxidation of Organic Compounds with KMnO4.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Solvent Free Ion Exchange Catalysis in the Oxidation of Organic Compounds with Sodium Bromate

The oxidation of organic compounds under solvent free ion exchange resin (IER) catalysis by sodium bromate has been studied at room temperature. Primary benzylic and secondary alcohols are converted to aldehydes and ketones and alkylarenes are oxidized to the corresponding α-ketones. The experimental procedure is simple and products are easily isolated in high yields at room temperature.

Ion Exchange Catalysis in Oxidation of Organic Compounds with KMnO4

The oxidation of organic compounds under ion exchange resin (IER) catalysis by KMnO4 has been studied in CH2Cl2 under reflux conditions. Secondary aliphatic and aromatic alcohols are converted to ketones, alkyl arenes and sulfides oxidized to corresponding ketones and sulfones, respectively, and thiols undergo oxidative coupling reactions to give disulfides. The experimental procedure is simple and products are easily isolated in good yields.

Continuous processes of ion-exchange catalysis, extraction, and ion exchanger regeneration, and the related technological features

Continuous processes of ion-exchange catalysis, extraction, and ion exchanger regeneration, and the related technological features

Reaction Distillation with Ion Exchangers

Abstract This paper studies batch distillation with reaction esterification of acetic acid and ethanol. The experimental investigation was carried out at atmospheric pressure in a column packed with ion exchanger Amberlite-120. The mathematical model was established by introducing reaction functions in material and enthalpy balance equations. The results obtained for the startup and product periods show advantages for reaction distillation with ion-exchange catalysis. A clean product is obtained, and there is no problem of wastewater or corrosion.

Cyanoethylation of Fatty Amines Using Acidic Ion Exchange Catalysis1

Cyanoethylation of Fatty Amines Using Acidic Ion Exchange Catalysis¹