New type of temperature variation of X-ray diffraction from a number of polymers

Autor:	K. A. Andrianov, V.Yu. Levin, V.S. Pankov, V. P. Zhukov, A. A. Zhdanov, D.Ya. Tsvankin
Rok vydání:	1979
Předmět:	chemistry.chemical_classification Diffraction Quantitative Biology::Biomolecules Electron density Intermolecular force General Engineering Analytical chemistry Polymer Thermal expansion Condensed Matter::Soft Condensed Matter chemistry X-ray crystallography Intensity (heat transfer) Macromolecule
Zdroj:	Polymer Science U.S.S.R.. 21:2348-2358
ISSN:	0032-3950
DOI:	10.1016/0032-3950(79)90176-x
Popis:	In contrast to the intensity reduction of X-ray reflexes normally observed on increasing the temperature of the polymers examined with an increase in temperature, both the intensity I and the integral intensity P of the main diffraction maximum, characterizing the inter-chain distance in the structure of these polymers, increase. Temperature variations of intensity are fully reversible. An increase in X-ray reflex intensity with an increase in temperature may be the result of thermal expansion, in which electron density of the main part of the macromolecule remains unchanged, but electron density in the boundary zone of intermolecular contacts decreases. These changes increase the intensity of the intermolecular diffraction maximum. A reversible increase in the intensity of diffraction maxima with an increase in temperature may be observed with fair thermal expansion using polymers with a large diameter of macromolecules ( ∼ 10–15 A ).
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::7cde3e52fa0430ac075c10f424fc58e7 https://doi.org/10.1016/0032-3950(79)90176-x Zobrazit plný text záznamu