| Autor: |
Matveev, Yuri, Askadskii, Andrey, Matseevich, Tatiana |
| Předmět: |
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| Zdroj: |
AIP Conference Proceedings; 2023, Vol. 2497 Issue 1, p1-7, 7p |
| Abstrakt: |
The influence of the amorphous-crystalline state on the molecular packing coefficients of polymers is considered. The structure of the amorphous-crystalline state of polymers has been clarified and the boundaries of changes in the crystalline and amorphous components have been determined. An expression for the packing coefficient of solvents has been obtained. Its analysis showed that liquids consist of dense and loose fractions with packing coefficients kd and kl. The packing coefficients of polymers and liquids are estimated using the ratio between the glass transition temperature to melting temperature =f(k) and the data of computer experiments. This made it possible to describe the dependence of the packing coefficients of dense k1 and loose k2 fractions on (Tg - To)/(Tm - To) over the entire range of their variation (0 < (Tg - To)/(Tm - To) < 0.734). It is shown that the packing coefficients k1 and k2 of polymers and liquids vary within limited limits in a wide range of temperatures, up to the vacuum temperature. For polymers: 0.745 < k1 < 0.71, 0.655 < k2 < 0.7, for liquids: 0.558 < k1 < 0.6, 0.364 < k2 < 0.539. The performed analysis is important for specifying the conditions of solubility of polymers, calculating the dielectric properties and surface tension coefficients of polymers and solvents. The results obtained are important for specialists working in the field of chemistry and physics to produce building materials with increased density and controlled solubility in organic solvents and in water. The latter is of prime importance for building materials for outdoor use to create materials that are resistant to rain and water purification agents.The method of molecular dynamics was used to study the structure of water from the point of view of the spatial packing of certain structural elements of the system (Delaunay simplexes - tetrahedra formed by the four nearest atoms that form an elementary cavity in the system under study), the shape of which is significantly deformed under the action of hydrogen bonds. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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