hydrolysis

The hydrolytic degradation of polyhydroxyalkanoates, polylactide and their mixtures in vitro in physiological solution and phosphate-salt buffer as well was researched. The hydrolysis intensity of biopolymers was evaluated via the mass loss, change in molecular weight as well as the water absorption applying the methods of infrared spectroscopy and complex thermal analysis. It was determined that films based on the researched biodegradable polymers thermostated in a phosphate-salt buffer have been degrading faster than in physiological solution.

The effect of concentrated nitric acid on the hydrolysis rate of ETS-40 ethyl silicate hasbeen studied. The duration and maximum temperature of ethyl silicate hydrolysis at different temperatures of the components have been determined. The formation of silica particles in the xerogel structure is shown. The influence of the ETS-40 hydrolysis on the particles size and concentration has been examined. The structure of the xerogel and the composition of the formed particles have been investigated using scanning electron microscopy (SEM) and energy dispersion analysis (EDX).

The influence of the bacterial α-amylase type and temperature on the accumulation of soluble dry matter and reducing sugars during fermentation of wheat batch has been investigated. The correlation between thermal stability of α-amylase and process parameters is shown. The initial activity of the enzyme preparation affects the starch hydrolysis intensity. The change in the enzymes activity, occurred due to their inactivation at high temperatures, affects the maximum content of dry matter and reducing sugars in the liquefied matter.

Purification of glucomannan by hydrolising starch – the main contaminant – was studied. Hydrolysis removed 88.7 % of starch. The highest glucomannan сontent was found to be 73.35 %. The sample showed the comparable infrared spectra to those of the commercial glucomannan. The kinetics of enzymatic hydrolysis was evaluated using the Michaelis-Menten model.

The paper presents the results of research of the separation of suspensions using flocculants based on polyacrylamide. The mechanism of the floccule formation, as well as polyacrylamide adsorption on the surface of clay particles, depending on the concentration of solids in suspension and flocculant costs are described. An optimal concentration of solids in suspension and flocculant consumption rate which the highest rate of the solid phase deposition is identified. Наведено результати дослідження процесу розділення суспензій з використанням флокулянтів на основі поліакриламіду.

The paper presents the results of research of the separation of suspensions using flocculants based on poly. The essence and process flokuloutvorennya polyacrylamide adsorption on the surface of clay particles, depending on the concentration of solids in suspension and flocculant costs. An optimal concentration of solids in suspension and flocculant consumption at which the highest rate of deposition of solid phase. Наведено результати дослідження процесу розділення суспензій з використанням гідролізованого флокулянта на основі поліакриламіду.

Reasons and mechanism of cordierite-mullite refractory materials destruction in the ovens for glazing ceramic wares baking have been examined. The change of elemental and phase compositions of refractory surface layers under the influence of cyclic action of water vapour and volatile components of glazing coating has been established. The ways of increasing cordierite-mullite refractory materials longevity have been proposed.