Macromolecular structure of coals. 9. Molecular structure and glass transition temperature

Abstract

The glass transition temperatures, Tg, of coal samples with a wide range of carbon content were determined by differential scanning calorimetry of untreated and pyridine-extracted coal particles. Their values varied from 580 to 632 K depending on the coal structure studied. During dynamic pyridine transport in coal samples, the value of Tg decreased as a function of solvent weight fraction. These results indicate a coal network structure behaving similarly to that of cross-linked synthetic polymer networks.

Potential of AFM–nanothermal analysis to study the microscale thermal characteristics in soils and natural organic matter (NOM)

“…A close look at the corresponding region in the DSC thermogram (see Fig. 3, right) indeed shows signs of a glass transition (visualized in the figure by the first derivative), although literature values indicate only T g > 580°C in coals (Lucht et al 1987;Larsen 1988). The suggested glass transition around this temperature in the charcoal is currently not supported by literature findings and needs to be verified in future research.…”

Pretreatment of coal by ionic liquids towards coal electrolysis liquefaction

“…connected by relatively strong bonds, such as ether bridge bonds, etc. [8]. And a small amount of low molecular weight constituents is trapped in the network [9].…”

Temporal change in the distribution patterns of hexachlorobenzene and dichlorodiphenyltrichloroethane among various soil organic matter fractions

“…Glassy domains are related to nonlinear adsorption isotherms and sorptionedesorption hysteresis due to a hole filling mechanism, whereas rubbery domains are proposed to account for linear sorption. The glass transitions were tested in isolated HA, FA (Hurrass and Schaumann, 2005), lignin (LeBoeuf and Weber, 2000), cellulose (Akim, 1978) and coal (Lucht et al, 1987), which verified that glassiness is a common characteristic of soil organic matter.…”