Modernization of the Catalyst Composition for the Synthesis of Acrylic Acid Nitrile in Aqueous and Non-Aqueous Media

The effect of the components of the catalyst solution for the hydrocyanation of acetylene on the activity and selectivity of the process under liquid-phase conditions has been studied. The introduction of ZnSO 4 and ZnO additives into the shop catalyst did not give a positive effect under these conditions. Studies of catalysts in non-aqueous media lead to an increase in their activity and selectivity in comparison with aqueous media. It has been shown that the composition of the CuCl - NMP - DMF catalyst is characterized by high activity (up to 32 g / l.h.) and selectivity (83-90%), i.e. the activity of this composition is almost twice as high as compared to the water-based ones (12-18 g l.h.).

Double metal cyanides as heterogeneous Lewis acid catalysts for nitrile synthesis via acid-nitrile exchange reactions

A series of transition metal-based double metal cyanides (DMCs) were studied as catalysts for the synthesis of nitriles via acid-nitrile exchange reaction.

A Rheometric Study of the Processes of Vulcanisation and Pore Formation of Elastomer foam Materials

Kinetic curves describing the processes of vulcanisation and pore formation of foam rubbers based on nitrile butadiene rubbers were studied. The curves were obtained using a D-MDR 3000 rheometer (MonTech) equipped with MonControl analytical software, which makes it possible, simultaneously with the measurement of the torque and tg δ, to determine the pressure in the chamber. The rubber compounds were noted for different stearic acid contents. The results of quantitative interpretation of the kinetic curves of processes of vulcanisation and pore formation in elastomeric materials are presented. Mathematical models for approximation of the curves of vulcanisation and pore formation, distinguished by high goodness of ft, are proposed. The relationship between the parameters of the models and the vulcanisation characteristics and the parameters of pore formation is established. The influence of the stearic acid content on processes of formation of the porous structure of foam rubbers based on blends of nitrile butadiene rubbers containing 27–30 wt% acrylic acid nitrile and polyvinyl chloride is shown.

The Influence of the Structural Organisation of Nitrile Butadiene Rubbers on their Vulcanisation

A comparative analysis of features of the vulcanisation of nitrile butadiene rubbers containing 18 wt% units of acrylic acid nitrile with different distributions of the AAN units along the macromolecules is carried out. The content of cis-1,4-, trans-1,4-, and 1,2-units was determined by IR spectroscopy (Bruker Equinox 55 Fourier spectrometer) from the intensity of the 730, 970, and 910 cm−1 absorption bands respectively. The dynamic viscosity at temperatures of 85 and 130°C and at shear rates of 1.13–42.23 s−1 and also the vulcanisation kinetics were determined on an Alpha Technologies RPA 2000 unit. The physicomechanical characteristics were determined using a Gotech AI-3000 instrument. The vulcanising system contained sulphur, ZnO, stearic acid, and an accelerator. The influence of the content of stearic acid on the properties of the vulcanisates was studied, and it was shown that the rubbers investigated can be divided into three groups. The authors suggest that the vulcanisation parameters and the physicomechanical characteristics of the elastomers are most influenced by the size of the alternating unit nanoformations.

In situ generation of nitrilium from nitrile ylide and the subsequent Mumm rearrangement: copper-catalyzed synthesis of unsymmetrical diacylglycine esters

A novel in situ generation of nitrilium from nitrile ylide and the subsequent Mumm rearrangement of carboxylic acid, nitrile, and diazo compounds gave various unsymmetrical diacylglycine esters.