Glass transition temperature calorimetrically determined

A glass transition temperature of about 40 C for the hydrated elastin sample (w = 0.14) fits fairly well into the glass transition temperature-water content curve calorimetrically determined by Kakivaya and Hoeve (23) for hydrated elastin. 

The determination of T of a blend is one of the calorimetric techniques used to elucidate the miscibility or partial miscibility in the amorphous phase of binary polymer blends. Glass transition temperature is the temperature at which the transition from the glassy to the rubbery state of the bulk material takes place. The establishment of miscibility using is based on the degree of dispersion of the second component in the amorphous region of the first component and that the size of the disperse phase domain is < 15 nm (Silvestre et al., 1996 Shultz and Young, 1980). It is noteworthy that blends which exhibit a are miscible whereas... 

Figure 30 Glass transition temperature fg of PMMA as measured by ellipsometry (filled symbols) and characteristic temperature r (at 120.74 Hz) measured by BDS (open symbols) plotted vs. layer thickness d. The measurements were carried out on different substrates having hydrophilic (a, Si/SiOjj to hydrophobic (b, gold coating c, silanized with hexamethyidisilazane (HMDS)) surfaces, (d) Additionally, covalently bonded PMMA brushes on Si/SiOx with strong attractive interfacial interactions were studied. The calorimetrically determined Tg of the bulk is shown by dashed lines, and the experimental error of 0.5 K (shaded region) is plotted for comparison. Reproduced with permission from Erber, M. Tress, M. Mapesa, E. U. etal. Macomolecules 2010, 43, 7729.2 ...

The PVC sample chosen as an experimental reference has a calorimetric glass transition temperature of Tg = 356 K and was purchased from Polyscience. The share of racemic diads was determined by solution -NMR... 

Changes in physical state may be observed from changes in thermodynamic quantities, which can be measured by calorimetric techniques, dilatometry, and thermal analysis. Spectroscopic methods are also available for the determination of changes in molecular mobility around transition temperatures. In addition to the changes in thermodynamic quantities and molecular mobility, a glass transition has significant effects on mechanical and dielectric properties. 

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