Influence of the Internal Structure and Intermolecular Interactions on the Correlation between Structural (α) and Secondary (β-JG) Relaxation below the Glass Transition Temperature in Neat Probucol and Its Binary Mixtures with Modified Saccharides was written by Minecka, A.;Tarnacka, M.;Jurkiewicz, K.;Hachula, B.;Kaminski, K.;Paluch, M.;Kaminska, E.. And the article was included in Journal of Physical Chemistry B in 2020.Related Products of 4163-60-4 This article mentions the following:
Broadband dielec. spectroscopy (BDS) has been used to study the mol. dynamics and aging process in neat probucol (PRO) as well as its binary mixtures with selected acetylated saccharides. In particular, we applied the Casalini and Roland approach to determine structural relaxation times in the glassy state of the examined systems (so-called isostructural times, τiso). Next, using the calculated τiso, primitive relaxation times of the coupling model were obtained and compared to the exptl. secondary β (Johari-Goldstein (JG) type) relaxation times. Interestingly, it turned out that there is a correlation between the β-JG and the structural (α)-relaxation processes below the glass transition temperature (T < Tg) in each investigated sample. This is a new observation compared to previous studies demonstrating that such a relationship exists only in the supercooled liquid state of neat PRO. Moreover, it was revealed that the stretching parameters obtained from the aging procedure are very close to the ones determined by fitting the dielec. data above the Tg with the use of the Kohlrausch-Williams-Watts function, indicating that the aging process is governed by the α-relaxation. Complementary Fourier transform IR and X-ray diffraction measurements allowed us to find a possible reason for these findings. It was demonstrated that although there are very weak intermol. interactions between PRO and modified saccharides, the intra- and intermol. structure of PRO is practically unaffected by the presence of modified saccharides. In the experiment, the researchers used many compounds, for example, (2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4Related Products of 4163-60-4).
(2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Related Products of 4163-60-4
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics