ДОСЛІДЖЕННЯ ВПЛИВУ ВМІСТУ ПІСКУ ТА МОДИФІКУЮЧИХ ДОБАВОК НА ВЛАСТИВОСТІ ПОЛІМЕРБЕТОННИХ КОМПОЗИЦІЙ

Purpose. Establishment of the influence of the content of sand and modifying additives on the hardness, compressive strength, and impact strength of polymer concrete compositions. Methodology. Polymer concrete compositions in the form of round pancakes, sticks and bars based on polyester resin of the CHROMOPLAST GP 2000 brand, hardener (organic peroxide for cold curing) of the Luperox K1 brand, cobalt stearate (cobalt salt of stearic acid), styrene and river sand were subject of investigation. Samples of polymer concrete composites were obtained in two stages: 1) mixing the resin with sand 2) the addition of hardener, styrene and cobalt stearate. To obtain a hardened polyester composition, metal forms with bent sides were used; ceramic boats (not enameled) metal molds 2 cm high. Preparation of the composition was carried out in the following sequence: first, resin was mixed with sand, then hardener, cobalt stearate and styrene were added. The following sequence of preparation of the composition also took place: first the resin and hardener were mixed, only then sand mixed with styrene and cobalt stearate was added. The forms were loaded into a heating cabinet and heated to a temperature of 100 °C for 30-40 minutes. After cooling in the form of the product was removed. The hardness, compressive strength and toughness of the developed compositions were investigated by standard methods. Results. It was found that an increase in sand content from 0 to 90% of the mass. in polymer concrete compositions leads to an increase in hardness by ~ 466%, as well as a decrease in compressive strength by ~ 62% and impact strength by ~ 50%. Scientific novelty. An increase in the hardness index and a decrease in the compressive strength and toughness of polymer concrete compositions with an increase in the sand content to 90 % of the mass was established. This is because the sand has a higher hardness than the polyester resin, and accordingly, an increase in its content leads to an increase in the hardness of the composition. The decrease in compressive strength and toughness is due to a decrease in the amount of binder, due to which the composition becomes more fragile. Practical value. The developed polymer concrete compositions can be used in construction, as well as for repairing damaged concrete surfaces and eliminating cracks.

Development of coalescents for paints and varnishes based on ionic liquids – the products of diethanolamine and inorganic acids interaction

This paper reports the synthesis of ionic liquids through the interaction between diethanolamine and orthophosphate and boric acids in order to establish the possibility of replacing volatile coalescents in a formulation for paints and varnishes with ionogenic compounds. The results from studying the influence of polymeric coalescents based on ionic liquids on the rheological properties of water-dispersion paints and varnishes of different nature are presented. It has been established that the synthesized coalescents could be used to modify the properties of paints and varnishes based on polyurethane and styrene-acrylic aqueous dispersions. It has been shown that the product of the interaction between diethanolamine and boric acid in aqueous solutions forms an ionogenic complex compound with a unipolar conductivity in terms of ОН─ ions. It was also established that when introduced to the formulation of water-dispersion paints and varnishes, the solutions of modifiers produce a diluting action. The influence of ionic liquids on the process of film formation of aqueous dispersions of polymers and pigmented paints and varnishes based on them was investigated. It was established that the synthesized ionogenic compounds are not inferior, in terms of their effectiveness, to the widespread conventional industrial coalescents of the Texanol→ type. Therefore, there is reason to assert the possibility of replacing the industrial coalescent Texanol→ in the formulation of pigmented water-dispersion paints and varnishes based on styrene-acrylic and polyurethane dispersions with fundamentally new synthesized ionogenic modifiers. Thus, the coatings with a coalescent based on ion liquid of diethanolamine borate have a higher level of conditional hardness, which exceeds by 17 % the hardness index of the paint made on the basis of the conventional Texanol→ type coalescent, without changing its decorative properties, such as color and shine

Effects of Metal Oxides on Carbonation and Coking of High-Salinity Organic Wastewater

Slag is difficult to treat quantitatively due to the formation of a molten mixture in the carbonization process of high-salinity organic wastewater. Thus, aiming at solving this difficulty, the effects of metal oxide additives, additive ratio, furnace burden ratio, and carbonization temperature on the carbonization and coking of high-salinity organic wastewater are systematically analyzed. The analysis is performed using scanning electron microscopy, X-ray diffraction, and Vickers hardness tests. The results show that all five metal oxide additives can reduce the hardness of carbonized products. The relative effect of reducing the coked hardness is as follows: MgO > CaO > kaolin > F e 2 O 3 > A l 2 O 3 . Thus, the effect of MgO on reducing the coking hardness is stronger than that of the other four metal oxides, reducing the hardness of carbonized products by approximately 81%. Furthermore, the adding charge can reduce the hardness index by at least 60%. When the carbonization temperature is higher than 800°C, the hardness index of the carbonized product decreases by approximately 5% each 50°C of increase in temperature. This study shows that the addition of metal oxides can effectively reduce the hardness of coking during the treatment of high-salt organic wastewater by carbonization and oxidation and provide theoretical support for the subsequent treatment of high-salt organic wastewater by carbonization and oxidation.

Development of Natural Rubber Latex Foam for Hand Exercising Application

This study has developed an alternative compounding formulation and process for natural rubber latex (NRL) foams for hand exercising application. Deprotenized natural rubber latex was used as raw material and a combination of DIXP and TBzTD, which were fugitive and high molecular weight accelerators, respectively, was used to lower allergenic potential and harmful nitrosamines. The NRL foams were prepared to various densities, characterized by Scanning Electron Microscopy (SEM) and tested for hardness index, accelerated ageing and compression set in comparison to the foams with conventional compounding formulation. With the same processes, the foams with these two different formulations were found to have similar densities and hardness indices. However, the foams using DIXP and TBzTD accelerators performed better in compression set and accelerated ageing tests.

Simulation of Winter Durum Wheat Flour Yield Based on Structural Equation Modeling

Flour yield determined the profitability of flour mill, but the intrinsic variability of the grain makes it very complex to analysis and estimate wheat grain flour yield. Simulation for flour yield attributes offer considerable advantages in flour mill, if reliable predictions of flour yield can be provided, because the wheat grain characteristics can be tested before milling. If this is possible, the characteristics thus observed could be quantified more reliably and objectively by Structural Equation Modelling (SEM). SEM was used to look for the most important wheat grain characteristics on flour yield, and then these wheat grain characteristics were used to simulate flour yield. Furthermore, the regressive equation was verified by the field experiment. The coefficient of variation of grain characteristics was low and distributed rather closely. The results of SEM showed that test weight had the most significantly effects on flour yield, followed by the hardness index. Test weight and hardness index could excellently estimate flour yield by multiplicative effect of test weight and hardness index, and which could determine 68% of the variation in flour yield. The simulation result can not only predict flour yield, but also look for the important grain characteristics for the flour yield.

Effectiveness Teston Hardness Performance of Plastic Waste and Sawdust Composite

The strength of a material is one option used to determine the use of forms. The use of plastics on product packaging is an efficient choice because plastics is light, practical and easy to forms. This study is done to measure the plastic waste hardness of mixed HDPE and PET type with teak tree sawdust which melted into two portions by the amount of 18 gram. This study finds the highest hardness index was achieved by the mixture of 1.5 gram of sawdust, 5 gram PET and 11.5 gram HDPE with the hardnesss point of 131. 3 N/mm under the 5000 gram pressure and temperatureof 100°C while the lowest point of 86.6 N/mm by the mixture of 1 gram sawdust, 625 gram PET and 10.7 gram HDPE under the 5000 gram pressure and temperature of 100°C. It can be seen that the lower the temperature of the mixture compositions, the better the hardness because the mixture is merged and binded better

THE CONTENT OF SOME TECHNOLOGICAL QUALITY COMPONENTS AND MYCOTOXINS IN GRAIN OF FOUR CULTIVARS OF SPRING WHEAT DEPENDING ON GRAIN STORAGE TIME AFTER HARVEST

The aim of this study was to determine the effect of three grain storage times and the cultivar factor on some parameters used in commodity analysis of spring wheat grains. A field experiment was conducted in Czeslawice (Poland) using the split-plot method in 3 replicates in 27 m2 plots. This paper presents the effect of storage time (3, 15, 27 months) of grain of four spring wheat cultivars (‘Korynta’, ‘Monsun’, ‘Tybalt’, ‘Zadra’) on some technological quality characteristics. After harvest, the grains were dried to the moisture content 14% and subsequently stockpiled in a warehouse. It was observed that grains can be stored for a period of even two years with no risk if all the grain storage rules are followed. Short- and long-term grain storage (3-27 months) resulted in satisfactory values of the grain quality characteristics like grain moisture, protein content, and grain hardness index. The storage of grain did not affect negatively grain contamination with mycotoxins. No significant differences were observed in the response of the cultivars studied (grain moisture content, protein content, grain hardness index) to grain storage time. Significant differences among the cultivars were observed in the grain hardness index after 3-month storage. It was also noted that the cultivars ‘Korynta’ and ‘Tybalt’ were characterized by lower susceptibility to contamination with mycotoxins than cvs. ‘Zadra’ and ‘Monsun’. The results obtained in this study are a good indicator for cereal producers who store grains for a period of even two years, thus becoming independent of changing price conditions in the cereals market and the changing demand for and supply of animal feed and bread grain across other countries.

EFFECTS OF CHEMICAL INTERESTERIFICATION ON THE PHYSICOCHEMICAL PROPERTIES OF PALM STEARIN AND RICE BRAN OIL BLENDS

Palm stearin (PS) and rice bran oil (RBO) were blended in the mass ratio of 100:0, 70:30, 50:50, 30:70 and 0:100. The oil blends were subjected to chemical interesterification (CIE) catalyzed by sodium methoxide (0.2% w/w). The following analysis were carried out before and after CIE: triacylglycerol (TAG) composition, slip melting point (SMP), solid fat content (SFC), microstructure, polymorphism and hardness index (HI). After chemical interesterification, there were decrease and increase in the amount of several TAG. Changes in TAG composition caused changes in the physical properties of the blends. Both SMP and SFC of all blends decreased significantly (p<0.05) after interesterification except for RBO. Chemical interesterification also reduced the eutectic interaction at 5°C. However, for hardness index, only blends with 50% and 100% PS decreased significantly (p<0.05) from 33.197 to 26.097 and 5.397 to 3.720, respectively. The crystals of the blends became smaller and reduced in number after interesterification. Interesterification promoted the formation of more β' crystals than β in all blends. The 30:70 PSRBO blend was the most suitable for margarine production as it melted close to body temperature.