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ANIONIC-POLYMERIZATION OF DIETHYLCYCLOSILOXANES - FORMATION OF LINEAR OLIGODIETHYLSILOXANES AND THEIR PHASE-TRANSITIONSстатья
Информация о цитировании статьи получена из
Web of Science
Дата последнего поиска статьи во внешних источниках: 9 марта 2017 г.
- Авторы: ZAVIN BG, RABKINA AY, KUTEINIKOVA LI, BLAGODATSKIKH IV, DUBOVIK II, GERASIMOV MV, PAPKOV VS
- Журнал: VYSOKOMOLEKULYARNYE SOEDINENIYA SERIYA A & SERIYA B
- Том: 37
- Номер: 3
- Год издания: 1995
- Первая страница: 507
- Последняя страница: 514
- Аннотация: Anionic polymerization of hexaethylcyclotrisiloxane (D-3(e)) and octaethylcyclotetrasiloxane (D-4(e)) initiated by potassium silanolate has been studied. According to the GLC and GPC data, the polymerization of strained D-3(e) includes the stage of rapid polymerizatlon followed by the stage of slower depolymerization. The polymerization of unstrained D-4(e) does not lead to the formation of a high-molecular poly(diethylsiloxane). In both cases, short-chain linear oligo(diethylsiloxanes) of the type KO-(D-e)(n)-K with n = 2 - 6 are formed in addition to the cyclic D-n(e) oligomers. Under the equilibrium polymerization conditions, active silanolate centers exhibit almost complete segregation in the linear short-chain oligo(diethylsiloxanes) of the type KO-(D-e)(n)-K. The data obtained indicate that poly(diethylsiloxane) is a thermodynamic unstable system, in which macromolecules can form only under unequilibrium polymerization conditions. The phase transitions in oligo(diethylsiloxanes) with M = 3140 and 11800 were studied by DSC and X-ray diffraction.
- Добавил в систему: Благодатских Инэса Васильевна