|
ИСТИНА |
Войти в систему Регистрация |
ИСТИНА ЦЭМИ РАН |
||
Formation of porous bodies from the mixtures of isotactic polypropylene with 1,2,4,5-tetrachlorobenzeneтезисы доклада
- Авторы: Pochivalov K., Basko A., Denisova Yu, Shandryuk G., Ezhov A., Kudryavtsev Ya
- Сборник: Book of abstracts. The 12th European Symposium on Thermal Analysis and Calorimetry (ESTAC12)
- Тезисы
- Год издания: 2018
- Место издания: Brasov, Romania
- Первая страница: 449
- Последняя страница: 449
- Аннотация: Recently we have constructed the full experimental phase diagram of isotactic polypropylene (iPP) – 1,2,4,5-tetrachorobenzene (TeCB) system using an original optical method. The data analysis was based on the concept that treats semicrystalline polymers as internally stressed microheterogeneous liquids with crystallites as the crosslinks of a macromolecular network. In contrast to the previously published diagrams, the new one contains an additional boundary curve that can be identified as the temperature dependence of the TeCB solubility in the amorphous regions of iPP or as the boundary at which an initially two-phase system transforms into a single-phase physical gel upon heating. With the new diagram, it is possible to formulate a physically consistent scenario of the mixture evolution under thermally induced phase separation and to predict the morphology of capillary-porous bodies that are formed after removal of the low molecular mass component upon cooling of the binary system. When a TeCB-enriched mixture is cooled down, one anticipates the formation of needle-like TeCB crystals from its solution in the iPP melt, which are uniformly distributed throughout the system. As soon as the full polymer amorphization temperature is reached, iPP crystallizes, whereas TeCB released in the course of the thermodynamically favorable phase separation crystallizes in its own phase. Cooling down of a mixture with the composition corresponding to the figurative point leads to a simultaneous crystallization of TeCB and iPP yielding the dispersion of TeCB crystals in the solid solution of TeCB in the amorphous regions of iPP. If a polymer-enriched mixture is cooled down, then firstly iPP crystallizes forming a single-phase microheterogeneous gel and, finally, TeCB crystallizes into its own phase dispersed within the polymer gel. Thermodynamic considerations are corroborated by DSC thermograms and illustrated with optical and scanning electron microphotographs that help to detalize the structure formation in capillary-porous bodies.
- Добавил в систему: Ежов Александр Анатольевич