Differential scanning calorimetry application

Chowdhry BZ, Cole SC. Differential scanning calorimetry—applications in biotechnology. TIBTECH 1989 7 11 18. 

Clas, S. D., Dalton, C. R. and Hancock, B. C. (1999). Differential scanning calorimetry application in drug development. Pharm. Sci. Technol. Today, 2,311-20. [250] Cleverly, B. and Williams, P. P. (1959). Polymorphism in substituted barbituric acid. 

Chiavaro, E., (ed.). (2015). Differential Scanning Calorimetry Applications in Fat and Oil Technology. CRC Press, Taylor Francis. 

The various terms appearing in these equations are self-evident. The differential heat release, dkidt, data are computed from differential scanning calorimetry (DSC). A typical DSC isotherm for a polyurethane reactive system appears in Fig. 11. Energetic composite processing is normally conducted under isothermal conditions so that Eq. (15) is more applicable. 

Barton, J. M. The Application of Differential Scanning Calorimetry (DSC) to the Study of Epoxy Resins Curing Reactions. Vol. 72, pp. 111 — 154. 

The techniques referred to above (Sects. 1—3) may be operated for a sample heated in a constant temperature environment or under conditions of programmed temperature change. Very similar equipment can often be used differences normally reside in the temperature control of the reactant cell. Non-isothermal measurements of mass loss are termed thermogravimetry (TG), absorption or evolution of heat is differential scanning calorimetry (DSC), and measurement of the temperature difference between the sample and an inert reference substance is termed differential thermal analysis (DTA). These techniques can be used singly [33,76,174] or in combination and may include provision for EGA. Applications of non-isothermal measurements have ranged from the rapid qualitative estimation of reaction temperature to the quantitative determination of kinetic parameters [175—177]. The evaluation of kinetic parameters from non-isothermal data is dealt with in detail in Chap. 3.6. 

A number of analytical techniques such as FTIR spectroscopy,65-66 13C NMR,67,68 solid-state 13 C NMR,69 GPC or size exclusion chromatography (SEC),67-72 HPLC,73 mass spectrometric analysis,74 differential scanning calorimetry (DSC),67 75 76 and dynamic mechanical analysis (DMA)77 78 have been utilized to characterize resole syntheses and crosslinking reactions. Packed-column supercritical fluid chromatography with a negative-ion atmospheric pressure chemical ionization mass spectrometric detector has also been used to separate and characterize resoles resins.79 This section provides some examples of how these techniques are used in practical applications. 

This paper reviews recycling technologies of PMMA waste, its applications and its markets. It relates in detail experimentation on thermal and oxidative depolymerisation of PMMA scrap, under nitrogen and oxygen atmospheres, at different heating rates by thermogravimetry and differential scanning calorimetry techniques. 15 refs. 

Mabrey-Gaud, S. (1981). Differential scanning calorimetry of liposomes, in Liposomes From Physical Structure to Therapeutic Applications (C. G. Knight, ed.), Elsevier, Amsterdam, pp. 105-138. 

Chemical structure of monomers and intermediates was confirmed by FT-IR and FT-NMR. Molecular weight distribution of polymers was assessed by GPC and intrinsic viscosity. The thermal property was examined by differential scanning calorimetry. The hydrolytic stability of the polymers was studied under in vitro conditions. With controlled drug delivery as one of the biomedical applications in mind, release studies of 5-fluorouracil and methotrexate from two of these polymers were also conducted. 

Thermal methods have found extensive use in the past as part of a program of preformulation studies, since carefully planned work can be used to indicate the existence of possible drug-excipient interactions in a prototype formulation [2], It should be noted, however, that the use of differential scanning calorimetry (DSC) for such work is less in vogue than it used to be. Nevertheless, in appropriately designed applications, thermal methods of analysis can be used to evaluate compound purity,... 

C. T. Mortimer. Differential Scanning Calorimetry. In Thermochemistry and Its Applications to Chemical and Biochemical Systems M. A. V Ribeiro da Silva, Ed. NATO ASI Series C, Riedel Dordrecht, 1984 47-60. 

M. J. Richardson. The Application of Differential Scanning Calorimetry to the Measurement of Specific Heat. In Compendium of Thermophysical Properties Measurement Methods, vol 2 K. D. Maglic, A. Cezairliyan, V E. Peletsky, Eds. Plenum New York, 1992 chapter 18. 

Sturtevant, J.M. 1987. Biochemical applications of differential scanning calorimetry. Ann Rev Phys Chem 38 463 -88. 

Wootton, B. M. and Bamunuarachchi, A. (1979). Application of differential scanning calorimetry to starch gelatinization. Starch/Starke 31, 201-204. 

Plato, C. and Glasgow, A.R., Jr. Differential scanning calorimetry as a general method for determining the purity and heat of fusion of high-purity organic chemicals. Application to 95 compounds, Anal. Chem., 41(2) 330-336, 1969. 

Crosslinked low-density polyethylene foams with a closedcell structure were investigated using differential scanning calorimetry, scanning electron microscopy, density, and thermal expansion measurements. At room temperature, the coefficient of thermal expansion decreased as the density increased. This was attributed to the influence of gas expansion within the cells. At a given material density, the expansion increased as the cell size became smaller. At higher temperatures, the relationship between thermal expansion and density was more complex, due to physical transitions in the matrix polymer. Materials with high density and thick cell walls were concluded to be the best for low expansion applications. 16 refs. 

More advanced techniques are now available and section 4.2.1.2 described differential scanning calorimetry (DSC) and differential thermal analysis (DTA). DTA, in particular, is widely used for determination of liquidus and solidus points and an excellent case of its application is in the In-Pb system studied by Evans and Prince (1978) who used a DTA technique after Smith (1940). In this method the rate of heat transfer between specimen and furnace is maintained at a constant value and cooling curves determined during solidification. During the solidification process itself cooling rates of the order of 1.25°C min" were used. This particular paper is of great interest in that it shows a very precise determination of the liquidus, but clearly demonstrates the problems associated widi determining solidus temperatures. 

Differential scanning calorimetry is applicable to the measurement of transition temperatures, specific heats, and heats of transition or reaction for all nonvolatile materials that do not evolve significant amounts of volatiles by reaction. The usual temperature range covered is -150 to 725°C. 

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