|
ИСТИНА |
Войти в систему Регистрация |
ИСТИНА ЦЭМИ РАН |
||
The study of dimethylcyclosiloxanes formation regularities in heterophase hydrolysis of a dimethyldialkoxysilaneтезисы доклада
- Авторы: Butuzov A.V., Cherkasova A.A., Ivanov P.V.
- Сборник: XVI International Scientific Conference with elements of school of young scientists «High-Tech in Chemical Engineering – 2016», Russia, Moscow, October 10–15, 2016
- Тезисы
- Год издания: 2016
- Первая страница: 26
- Аннотация: It is well known that the question of the relationship between linear and cyclic products in the hydrolytic polycondensation (HPC) organochlorosilanes and organoalkoxysilanes was discussed repeatedly during the formation at the beginning of the production of silicones and discussed today. In the late 90-ies, the results published in the area of macrokinetics of heterophase hydrolysis of a diorganodichlorosilanes allowed to purposefully steer the process toward the formation of only the cyclic or linear products [1]. Due to the fact that the difference in reactivity of organoalkoxysilanes and organochlorosilanes may cause a completely different ratio homofunctional (HMPC) and heterofunctional condensation (HTFC), affecting the composition of hydrolysis products was of interest to study the HPC diorganodialkoxysilanes. The report provides comparative data on the formation of linear and cyclic products in HMPC (CH3)2Si(OH)2 and partial hydrolysis (PH) (CH3)2Si(OR)2 (R = Me, Et, iPr, Bu). This problem was solved by studying the composition of hydrolysis products (CH3)2Si(OR)2 depending on the ratio water/monomer at different temperature, concentration of catalyst, nature of solvent (such as dioxane, acetone, acetonitrile, n-hexane, nitromethane, THF, MTBE, toluene, ethyl acetate), order and rate of input of reactants. The GLC method was used to estimate composition of products and nature of chain. As a result, we have found that the quantitative yield (close to 100 %) of dimethylcyclosiloxanes is achieved under non-equilibrium conditions on the mechanism HTFC when the molar ratio of the reactants [H2O]/[(CH3)2Si(OR)2] = 1, the final composition of the products of hydrolysis depends little on temperature, concentration of catalyst, nature of solvent (such as water-miscible and not miscible), the nature of the functional group, the order and speed of input of reactants. The resulting investigation of the laws of the hydrolysis of (CH3)2Si(OR)2 can be the basis for an effective technology of obtaining of organomethylcyclosiloxanes.
- Добавил в систему: Бутузов Александр Владимирович