Problems of Chemistry and Chemical Technology

Influence of Amphoterous Polymer Resin on Indexes of Dehydration of Pulp and Paper Quality

Influence of amphoterous polymer resin “Ultrares 200” on forming process and strength properties of paper from wastepaper was investigated. It was established, that increasing of beating rate of pulp leads to decreasing of pulp dehydration rate. It was concluded, that grinding shortens and partially fibrillates fiber, increasing their surface leading to better swelling and retention of water by fibers.

Investigation of Various Stages Process for Producing Microcrystalline Pulp from Hemp for its Quality Indicators

A comparative analysis of the chemical composition of the hemp fibers and stalks with cotton and representatives of hardwood and softwood was performed. The possibility of obtaining microcrystalline cellulose from hemp fibers by alkaline sulfite-alcohol delignification with preliminary acid and alkaline hydrolysis was investigated. It was found that carrying out an acid and an alkali pre-hydrolysis reduces the mineral content and partly of residual lignin in the plant material.

Electromotive Force at Etching Homogeneous Magnetized Steel Cylinder in the Electrolyte

In this paper, we calculate the electric cell voltage of the physical circuit at etching of ferromagnetic electrode in the form of a cylinder in an electrolyte caused by inhomogeneous distribution of concentration of the paramagnetic corrosion products on the surface of a steel cylinder in an inhomogeneous magnetostatic field. The shape of the electrode was chosen because all points of the cylinder surface are equivalent in this model system in the absence of magnetization and effects of the magnetic field can be easily separated from the effects of a different nature.

Dissolution Silver in Plasma Chemically Activated Solutions

This study suggests the possibility and efficiency of application solutions treated under the contact non-equilibrium low-temperature plasma for intensification dissolution of silver in cyanide leaching systems. The obtained research results show that plasma activated solutions due to the complex of peroxide and super peroxides compounds, radicals and particles formed in water during processing have higher oxidizing properties compared to synthetic hydrogen peroxide and oxygen commonly used in the hydrometallurgical industry as oxidizing component.

Investigation Inhibition Properties of Volatile Atmospheric Corrosion Inhibitor Based on Natural Material

The aim was to study the component composition of the volatile compounds of hops isopropanol extract and evaluation of physical and chemical properties of the new film on the metal surface. The volatiles extract of hope cones are analysed by Gas Chromatography Mass Spectrometry (GC–MS). Based on the data of the gas chromatography-mass spectrometry we identify the qualitative composition of the volatile compounds of the extract hops “Aromatic”. The main components are terpenoids, ketones, phenolic compounds, phenol and phenol carboxylic acid.

Microcrystalline Cellulose from Bast Plants

It was found that the chemical composition of flax fiber is common to cotton fiber, but differs from the stems of hemp and kenaf, softwood and hardwood because of higher content of ash, lesser lignin and pentosans content. Stems of hemp and kenaf compared with wood at approximately the same cellulose content have lesser lignin content, ash content and a much larger number of substances that dissolve in water and NaOH.

Deactivation of Catalyst in System “Consecutive Reaction Α1→ α2Α2→ α3Α3 + Catalyst + Mixing Continuous Reactor”

In this paper, we obtain the analytic solution of the problem describing the non-stationary functioning mode of the system caused by deactivation of the solid catalyst. This mode is expressed in consecutive reaction Α1→ α2Α2→ α3Α3 + catalyst + mixing continuous reactor.

Phase Phase Composition and Melting Features of Mineral Raw Material from Ukrainian Deposits used for LAS-Ceramics Production

This paper describes how Li-glass is obtained and studied. Using this glass, Li2O-Al2O3-SiO2 – based glass-ceramics materials are produced. They play an important role in industry as materials with specific properties. Glass-ceramics materials feature high strength, low coefficient of thermal expansion, chemical and thermal stability, refractoriness etc. To obtain LAS-сeramics, we obtain separate fraction petalite, study their chemical composition, select and calculate the composition of the Li-glass charge. In addition, the heat treatment of the obtained received samples is carried out.

Application of Computer Modeling to Predict the Chromatographic Analytes Behavior

This paper analyzes the capabilities of QSRR. Moreover, we make an insight into brief theoretical information on this method development and provide a list of issues to be solved by dint of it and the issues that may arise during obtaining QSRR models. We present the classification of descriptors and software used in construction of models and a list of basic mathematical algorithms rejecting irrelevant descriptors. The advantages and disadvantages of existing QSRR models used in HPLC method are pointed out.

The Surface Functionalization of Multiwalled Carbon Nanotubes

The aim of this paper is to develop methods of oxidation of multiwalled carbon nanotubes (MWCNTs) and determine their functional dependence on oxidation conditions. Based on initial MWCNTs we synthesize three series of samples oxidized under different conditions: by concentrated hydrogen peroxide mixed with sulfuric acid under standard conditions, by concentrated hydrogen peroxide mixed with sulfuric acid during boiling, by concentrated nitrate acid at temperatures of 50, 75 and 100 оC.