http://ea.donntu.ru/handle/123456789/25954 2014 г. 2026-04-20T01:28:46Z http://ea.donntu.ru/handle/123456789/25992 Title: Эпоксидирование подсолнечного масла в системах на основе пероксида водорода и органических кислот Authors: Сердюк, А. А.; Касянчук, М. Г.; Опейда, И.А.; Ткаченко, Т.Н.; Сердюк, А. И. Abstract: Эпоксидирование растительных масел является важным промышленным процессом. В статье рассмотрено влияние ряда условий (состав эпоксидирующей смеси, время реакции, перемешивание) на выход продукта эпоксидирования масла подсолнечника. Показано, что оптимальным является использование муравьиной кислоты и пероксида водорода при интенсивном перемешивании в больших объемах и с постепенным добавлением в реакционную смесь пероксида. Description: Epoxidation of vegetable oils is an important industrial process, as the products are used as plasticizers and stabilizers for polymers production. For example, halides are released during operation and recycling of halogen-containing polymers (halobutyl and polyvinyl chloride). This is the main reason for the rapid degradation of the polymer, corrosion of equipment and harm to human health. For preventing this process stabilizing agents, which capable of absorbing hydrogen halides are introduced into the polymer. There are numerous methods for the epoxidation of vegetable oils. However, many of them require using of uncommon and / or expensive catalysts, and sometimes require additional costs for the elimination and purification of the final product. This article focuses on the selection of epoxidation conditions that would ensure high yields when using the most simple techniques, environmentally friendly and cheap reagents. Sunflower oil is interested for use in the epoxidation process, because it contains a significant amount of mono- and polyunsaturated fatty acids, and has a low cost and high volume production in our country. Influence of conditions (composition epoxidation mixture, reaction time, stirring) to yield the epoxidation of sunflower oil discussed in the article. The use of cation exchanger KU-2-8 (which can be a carrier of the active catalytic centers) or effective catalyst for many oxidation processes — N-hydroxyphtalimide not affect the yield of the desired product. It is shown that the best is to use formic acid and hydrogen peroxide under intensive stirring in large quantities and with the gradual addition of peroxide to the reaction mixture. Yield epoxidized sunflower oil was ≈ 72% according to 1H-NMR spectroscopy (decrease of the proton signals of the double bonds in comparison with the original signals in sunflower oil evaluated). 2014-01-01T00:00:00Z http://ea.donntu.ru/handle/123456789/25991 Title: Выбор способа получения твердых углеводородных пен на основе каменноугольного пека Authors: Крутько, И.Г.; Колбаса, В.А.; Сацюк, К.А. Abstract: В статье обосновывается выбор прессовой технологии для получения твердых углеводородных пен на основе каменноугольного пека. Рассматриваются стадии получения пековых пен, а также основные факторы, которые влияют на процесс вспенивания. Description: Possible methods of solid hydrocarbon foams producing based on coal tar pitch are observed in article. Disadvantages of methods are also considered. On the basis of preliminary studies extrusion technology was selected for coal tar pitch foaming. According to extrusion technology the liquor of coal tar pitch with a chemical gasifier agent is heated and maintained under pressure until complete decomposition of CGA and dissolving of gaseous products in coal tar pitch. Then, while pressure reset the foaming process occurs. The structure is fixed by viscosity increasing of coal tar pitch during cooling. Absence of free surface in foam and high speed of its lift reduces the possibility of dense crust formation. Structure and properties of gas-filled materials depend on many factors, but the temperature and pressure are the most important. Also contemplated stages of pitch foams production: size reduction and mixing of components, compression the powder mass to form for foaming and its placing in a pressure vessel, heating the mixture to a temperature above the melting point of coal tar pitch, soaking the liquor under pressure in an autoclave for the time necessary for decomposition of gasifier agent . 2014-01-01T00:00:00Z http://ea.donntu.ru/handle/123456789/25990 Title: Дослідження властивостей материалу для відновлювального ремонту вогнетривкої кладки Authors: Горбатко, С.В. Abstract: Максимально можливе подовження терміну служби коксових батарей досить актуальне завдання, яке виникає при експлуатації подібних теплових агрегатів. Одним з видів ремонтів є метод відновлення кладки за технологією керамічного наплавлення, який застосовується для ремонту пошкоджень будь-якої складності. Відмінними характеристиками цього процесу є те, що в якості горючих компонентів виступають метали в елементному стані, а як окислювач кисень. Можливість застосування даного методу і сумішей для ремонту вогнетривкої кладки є актуальними, що дозволяє вирішити цілий ряд питань з продовження терміну служби робочої зони камер коксування. Description: The problem about resistance of the brickwork for coke-oven batteries arises during their exploitation. Hence, maximal enlargement of its operation life is of present interest. Successful solution of this problem defines the main technical and economic parameters of the whole heat unit. In the process of brickwork the coking chamber subjected to systematic variations in temperature, which affects the duration of the refractory brickwork. Arising in the surface layer refractories thermal stresses exceed the tensile strength at break of the refractory and lead to its destruction resulting in impaired sealing heaters partitions. Destruction of refractory chamber doors flows at different times of operation with varying intensity. Form of destruction, their density in the zones of different refractory brickwork. Moving mass of coke and carbonaceous deposits that negatively affects the brickwork. During operation, the emergency stop with cooling masonry that causes destruction of refractories. One type of repair is a method of restoring masonry ceramic welding technology, which is applicable to repair damage of any complexity and virtually eliminates any damage to masonry coking chamber. This is the kind of "hot" refractory masonry repairs allowing cause refractory coating without thermal shock heated material refractory brickwork. The distinguishing characteristics of this process is that as the combustible components in the elemental metals are the state and oxygen as the oxidant. Temperature of the process varies within the range from 1900 °K to 3000 °K. The possibility of applying this method to repair and mixtures of refractory brickwork are relevant, allow us to resolve a number of issues in extending the life of the working area of coking chambers. 2014-01-01T00:00:00Z http://ea.donntu.ru/handle/123456789/25989 Title: Влияние типа водной среды на наследственную склонность к коррозии деформированной высокопрочной проволоки Authors: Алимов, В.И.; Пушкина, О.В.; Дзюба, Т.В. Abstract: Изучено влияние состава и рН водной среды на коррозионное разрушение предварительно холоднодеформированной углеродистой стали. Получены количественные характеристики скорости электрохимической коррозии, которые следует учитывать при конструировании изделий из изученных материалов и назначении эксплуатационных требований к ним. Description: During operation there is interact of wire and wire products with various aggressive mediums, so it is important to know to what extent the consequences of cold deformation effect on interaction of the deformed metal with an aqueous medium of varying acidity and composition. The purpose of this work is to measure the hereditary susceptibility for electrochemical destruction of cold high-tensile wire due to the type, origin and aqueous medium corrosive acidic. The samples of wire from steel 85 (0,83% of carbon) dia. 2 mm and a length of 30 mm with degrees of pre-deformed by cold plastic deformation to 0 - 75 % were used in the experiments. To simulate the acidic media used 5% solution of sulfuric acid in distilled water, to simulate a neutral media - water of natural water sources. Noteworthy is the fact that the rate of corrosion in acidic media of three orders of magnitude higher then speed in neutral media. For small degrees of deformation higher corrosion resistance exhibit samples in media with large pH, but with increasing degree of deformation shown an inverse relationship, but with increasing of time delay differences in the rate of corrosion in aqueous media are disappeared. 2014-01-01T00:00:00Z