Comparison with differential scanning calorimetry

Semerak SN, Frank CW (1983) Excimer fluorescence as a molecular probe of blend miscibility—comparison with differential scanning calorimetry. Adv Chem Ser 203 757-771... 

R. H. Wrlson, B. J. Goodfellow, P. S. Belton, B. G. Osborne, G. Oliver, P. L. Russell. Comparison of Fourier Transform mid infrared reflectance spectroscopy with differential scanning calorimetry for the study of the staling of bread. J Sci FoodAgric 54 471-483, 1991. 

Probably the main weakness of DTA as a method of analysis remains the difficulty of linking the thermal changes shown on the thermogram, with the actual thermal processes taking place. It should be noted that data obtained by DTA are often similar to those available for differential scanning calorimetry. Indeed the two techniques overlap extensively and may be seen as complementary. A comparison of the two techniques is made at the end of the next section. 

The preparation of immiscible polymer blends is another way to disperse a bulk polymer into fine droplets. It has been reported for several polymers that when they are dispersed in immiscible matrices into droplets with average sizes of around 1 pm, they usually exhibit multiple crystallization exotherms in a differential scanning calorimetry (DSC) cooling scan from the melt (at a specific rate, e.g., 10 Cmin ). Frensch et al. [67] coined the term fractionated crystallization to indicate the difference exhibited by the bulk polymer, which crystallizes into a single exotherm, in comparison with one dispersed in a large number of droplets, whose crystallization is fractionated temperature-wise during cooling from the melt. 

Figure 7.53. Differential scanning calorimetry (DSC). Shown are (a) schematic of the heat-flux sample chamber (b) an example of a DSC thermogram, showing endothermic eventsbDf (c) DSC thermogram of a poly(vinyUdene fluoride)-ethyl acetoacetate polymer-solvent system, showing two melting events for the polymer due to its intermolecular interactions with solvent molecules. The inset shows a comparison between the pure polymer (b) and the polymer-solvent (a). Reproduced with permission from Dasgupta, D. Mahk, S. Thierry, A. Guenet, J. M. Nandi, A. K. Macromolecules 2006, 39,6110.

Comparison of several techniques (namely Fourier transform infrared spectroscopy (FTIR), simultaneous thermogravimetric analysis-differential scanning calorimetry (TGA-DSC) and ultrasonic spectroscopy) for assessing the residual physical and mechanical characteristics of polymer matrix composites (PMCs) exposed to excessive thermal loads showed the measured power spectra of ultrasonic energy to correlate with performance of graphite fibre epoxy matrix composites exposed to thermal degradation, and also that analyses with the three techniques all pointed to the same critical temperature at which thermally induced damage increased sharply [58],... 

In most cases, the purity of a pharmaceutical substance is determined by comparison of the reference standard with the known purity assigned. On the other hand, when no reference standard sample is available, the purity is determined by an absolute method in which the calculated result is based on theory and not by a comparative method. Purity established by analytical methods such as phase-solubility analysis or differential scanning calorimetry (DSC) is known as absolute purity (Figs. 3 and 4). 

A study of the phase behavior of (poly-f-butylmethacrylate)n - (polystyrene)n and (poly-t-butylacrylate)n - (polystyrene), miktoarm stars by differential scanning calorimetry has shown a remarkable decrease in the Tg of the polystyrene phase, in comparison with linear precursors, and an increase in the width of the glass transition [360]. An intermediate Tg was observed in some cases for microphase separated samples. The above phenomenon was attributed to an extended interphase region in these materials, due to partial mixing of the different chains around the cores of the stars. 

Song, M., Liebenberg, W. and de Villers, M.M. (2006) Comparison of high sensitivity micro differential scanning calorimetry with X-ray powder diffractometry and FTIR spectroscopy for the characterization of pharmaceutically relevant non-crystalline materials. Die Pharmazie, 61... 

Thermoelectrometry techniques are not wideiy employed in thermal analysis, in fact, they may be described as neglected techniques in comparison with the widely used thermogravimetry iTGl differential thermal analysis (DTA). and differential scanning calorimetry iDSC) techniques. Nevertheless, they are important for certain specific applications, many of which will be discussed here. 

The morphology of the materials must also be important. Large changes in creep were found for very small changes in the degree of crystallinity as measured by x-ray techniques or by differential scanning calorimetry (DSC). This is apparent from a comparison of the creep data with data on crystallinity index and apparent heat of fusion (Table I). The crystallinity index is the area above the amorphous curve divided by the total area obtained from an... 

Differential Scanning Calorimetry has been used for studying the interaction of labdanes 1 (labd-13(E)-ene-8o,15-dio1), 2 (labd- 3(E)-cne-8u-ol-15-yl-acetate) and 3 (labd-14-ene-8,13-diol (Sclareol)) Fig. (12) [76-77] with DPPC model lipid bilayers. The thermotropic changes caused by the labdanes in DPPC bilayers could be used for evaluating the incorporation efficiency of labdanes in DPPC liposomes. Furthermore in these studies [29, 76], a comparison with die structurally similar molecule to cholesterol was carried out based on their thermotropic behavior. The development of liposomal formulations incorporating 1 and 2 has been achieved, while the stability studies of the liposomal formulations based on -potential and on liposomal size have been evaluated. 

Yang DP, Mavromoustakos T, Beshah K, and Makriyannis A (1992) Amphipathic interactions of cannabinoids with membranes. A comparison between delta 8-THC and its O-methyl analog using differential scanning calorimetry, x-ray diffraction and solid state 2H-NMR. Biochim Biophys Acta 1103 25-36. 

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