Особенности синтеза триамилцитрата

Objectives. To find an effective way for obtaining triamyl citrate, an environmentally friendly, biodegradable citric acid ester used as a plasticizer for PVC-based polymer compositions.Methods. The possibilities of heterogeneous catalysis were analyzed using the case study of three commercial samples of macroporous sulfocationites (Amberlyst™ 15, Amberlyst™ 70, and TULSION® 66). Homogeneous catalysis was studied using the example of orthophosphoric acid (H3PO4), while self-catalysis was investigated during esterification of citric acid with amyl alcohol (ROH). The syntheses were carried out under identical conditions: T = 110 °C, the ratio of CA:ROH = 1:5 (mol) amount of catalyst 1 wt % on the reaction mass in a thermostatically controlled reactor of ideal mixing with continuous distillation of the resulting water.Results. It was found that in all variants (even under self-catalysis conditions), the conversion of citric acid in 180 min reached 94–99%. Triamyl citrate was formed after 9 h with a yield of 90% only when using a homogeneous catalyst (H3PO4) and in the presence of a heterogeneous catalyst sample (Amberlyst ™ 15).Conclusions. The revealed differences in the reactivity of the studied sulfocationites (Amberlyst™ 15, Amberlyst ™ 70, and TULSION® 66) confirm the well-known theoretical positions, according to which the kinetic pseudo-homogeneous model of the esterification process of hydroxy acids in excess of aliphatic alcohols is based on the law of acting masses and depends on the specific surface area of the catalyst, which for Amberlyst ™ 15 is of the greatest importance as compared to Amberlyst ™ 70 and TULSION® 66 (m2/g): 53:36:35, respectively.Цели. Поиск эффективного метода получения триамилцитрата – экологически чистого, биоразлагаемого сложного эфира лимонной кислоты, используемого в качестве пластификатора полимерных композиций на основе поливинилхлорида.Методы. Выявлены возможности гетерогенного катализа на примере трех коммерческих образцов макропористых сульфокатионитов (Амберлист™ 15, Амберлист™ 70 и Тулсион® 66); гомогенного катализа на примере ортофосфорной кислоты (H3PO4) и самокатализа при этерификации лимонной кислоты (ЛК) амиловым спиртом (ROH). Синтезы проводили в одинаковых условиях: T = 110 °С отношение ЛК:ROH = 1:5 (мольн.) количество катализатора 1 мас. %. на реакционную массу в термостатированном реакторе идеального смешения с непрерывным отгоном образующейся воды.Результаты. Установлено, что во всех вариантах конверсия лимонной кислоты за 180 мин достигает 94–99%. Триамилцитрат с выходом 90% образуется через 9 ч только при использовании гомогенного катализатора (H3PO4) и в присутствии образца гетерогенного катализатора – Амберлист™ 15.Выводы. Выявленные различия в реакционной способности исследованных сульфокатионитов Амберлист™ 15, Амберлист™ 70 и Тулсион® 66 подтверждают известные теоретические положения, в соответствии с которыми кинетическая псевдогомогенная модель процесса этерификации гидроксикислот в избытке алифатических спиртов основывается на законе действующих масс и зависит от удельной поверхности катализатора, которая для Амберлист™ 15 имеет наибольшее значение по сравнению с Амберлист™ 70 и Тулсион® 66 (м2/г): 53:36:35 соответственно

TEMPERATURE FIELDS MODELING IN THE RESIDENTIAL PREMISES WITH DIFFERENT SIZES OF THE HEATING DEVICE

This article is devoted to the modeling and study of temperature fields in a residential area with different sizes of steel panel radiator. The paper presents a comparison of the simulated fields and obtained conclusions on the selection of heating devices.В статье рассматривается моделирование температурных полей в жилом помещении с различными типоразмерами стального панельного радиатора. В работе изложено сравнение смоделированных полей и получены выводы по подбору отопительных приборов

Use of Technogenic Silica Fume and Brown Coal Semi-Coke in the Technology of Silicon Carbide

The paper describes thermodynamic experiments to determine the optimal temperature and time modes for the carbide production process from the briquette charge comprising silica fume and brown coal semi-coke, conditions for chemical enriching of silicon carbide, its phase, chemical and granulometric compositions and particle morphology

Theory of rotating electrohydrodynamic flows in a liquid film

The mathematical model of rotating electrohydrodynamic flows in a thin suspended liquid film is proposed and studied. The flows are driven by the given difference of potentials in one direction and constant external electric field E-out in another direction in the plane of a film. To derive the model, we employ the spatial averaging over the normal coordinate to a film that leads to the average Reynolds stress that is proportional to vertical bar E-out vertical bar(3). This stress generates tangential velocity in the vicinity of the edges of a film that, in turn, causes the rotational motion of a liquid. The proposed model is used to explain the experimental observations of the liquid film motor

Allocation of Oil Potential Zones Based on the Correlation of the Upper Vendian Permeable Layers by the Borehole Logging Methods

According to study of the large volume of the actual data from the wells located in the Udmurt Republic and the Perm kray, the correlation schemes were constructed to indicate the extension of the Upper Vendian reservoirs in the wells sections. The range of reservoirs extension was identified. The analysis of the obtained data allowed defining the priority directions of the further study of the Vendian oil and gas potential