Calorimeter differential thermal analysis

Dough Moulding Compound Dynamic Mechanical Thermal Analysis Direct Resin Injection and Venting Differential Scanning Calorimeter Differential Thermal Analysis Elongation at Break... 

Differential scanning calorimetry/calorimeter Differential thermal analysis Derivative thermogravimetric Differential temperature under load Divinylbenzene... 

ARC = Accelerating Rate Calorimeter (Columbia Scientific Instrument Corp.) DSC = Differential Scanning Calorimeter DTA = Differential Thermal Analysis RC1 = Reactor Calorimeter (Mettler-Toledo Inc.) RSST = Reactive System Screening Tool (Fauske and Associates) VSP = Vent Size Package (Fauske and Associates) ... 

Figure 2.6C shows the temperature difference between reference and sample as recorded by differential thermal analysis (DTA). Note also the similar differential scanning calorimeter (DSC) curve later in Figure 2.13. 

E. S. Watson, M. J. O Neil, J. Justin,N. Brenner.X Differential Scanning Calorimeter for Quantitative Differential Thermal Analysis. Anal. Chem. 1964, 36, 1233-1238. 

The glass transition (Ta) and melting (Tm) temperature of the pure component polymers and their blends were determined on a Perkin-Elmer (DSC-4) differential scanning calorimeter and Thermal Analysis Data Station (TADS). All materials were analyzed at a heating and cooling rate of 20°C min-1 under a purge of dry nitrogen. Dynamic mechanical properties were determined with a Polymer Laboratories, Inc. dynamic mechanical thermal analyzer interfaced to a Hewlett-Packard microcomputer. The... 

Differential thermal analysis was performed with the DuPont 900 differential thermal analyzer the heating rate was usually 10°C. per minute. To determine heats of reaction, the calorimeter attachment to the Du Pont instrument was employed. Planimeter determinations of peak areas were converted to heat values by using standard calibration curves. For the infrared spectra either a Beckman IR5A instrument or a Perkin Elmer 521 spectrophotometer with a Barnes Engineering temperature-controlled chamber, maintained dry, was used. Specimens for infrared were examined, respectively, as Nujol mulls on a NaCl prism or as finely divided powders, sandwiched between two AgCl plates. For x-ray diffraction studies, the acid-soap samples were enclosed in a fine capillary. Exposures were 1.5 hours in standard Norelco equipment with Cu Ko radiation. For powder patterns the specimen-to-film distance was 57.3 mm. and, for long-spacing determinations, 156 mm. 

Watson, E. S., O Neill, M. J., Justin, J. and Brenner, N. 1964. A differential scanning calorimeter for quantitative differential thermal analysis. Anal. Chem. 36, 1233— 1237. 

The reactivity value is obtained by using the peak temperature of the lowest differential thermal analysis (DTA) or differential scanning calorimeter (DSC) exotherm value as shown in column 2 of Table VI. Alternatively, it can be obtained from a qualitative description of the instability (or... 

In some instances, an adiabatic bomb calorimeter may not be available or the sample may be too small for accurate use. To combat such problems, there is evidence that differential thermal analysis (DTA) is applicable to the determination of the calorific value of coal. Data obtained by use of the DTA method are in good agreement with those data obtained by use of the bomb calorimeter (Munoz-Guillena et al., 1992). 

For the determination of reaction parameters, as well as for the assessment of thermal safety, several thermokinetic methods have been developed such as differential scanning calorimetry (DSC), differential thermal analysis (DTA), accelerating rate calorimetry (ARC) and reaction calorimetry. Here, the discussion will be restricted to reaction calorimeters which resemble the later production-scale reactors of the corresponding industrial processes (batch or semi-batch reactors). We shall not discuss thermal analysis devices such as DSC or other micro-calorimetric devices which differ significantly from the production-scale reactor. 

Groszek (1966) early developed a simple flow-through adsorption calorimeter, which is somewhat similar to a differential thermal analysis (DTA) system (because of its single-point temperature detector) and is therefore well suited for the detection of thermal effects and for screening experiments. To obtain meaningful results requires more sophisticated equipment, however. A heat flowmeter microcalorimeter is normally used for this purpose. Such a microcalorimeter, especially designed for liquid-flow adsorption and for the complementary determination of AmitH, is illustrated in Figure 5.18. 

Differential Thermal Analysis (DTA). These thermal profiles were obtained using a calorimeter cell with a DuPont 900 DTA instrument. Samples were cut from molded or cast films of these polymers, and they weighed 10-20 mg. A programmed heating rate of 10°C/min and a sensitivity of 0.2 /inch were used in this study. All thermal profiles were obtained with the sample flushed with an N2 stream. 

The usual scanning techniques are differential thermal analysis (DTA) [78] and differential scanning calorimetry (DSC) [79-81], In these methods it is assumed that the heat loss from the calorimeter is a function of temperature only. By comparing the rate of heat input and temperature rise for a polymer sample with that of a standard, usually synthetic sapphire, the specific heat of the polymer can be obtained. 

E 1356 (1998) Test method for glass transition temperatures by differential scanning calorimeter or differential thermal analysis... 

Differential scanning calorimetry A Perkin-Elmer DSC-2 calorimeter with Thermal Analysis Data Station was used. The calorimeter was calibrated according to manufacturer s specifications. Heats of reaction were calculated from the peak areas using indium as a standard (AH=6.80 cal/g). Tg was taken as the onset of the endothermic deflection. The heating rate was set to 20 /min. For DSC analysis, samples were prepared by two techniques a) vacuum drying of varnish and b) by flaking off resin from prepreg. 

Historically, DSC is a development of differential thermal analysis (DTA) and both techniques have a common origin in the measurement of temperature. The fundamental concept of both techniques is sim-ple-to measure thermal changes in a sample relative to a thermally inert reference as both are subjected to a controlled temperature program. In classical DTA, the temperature difference between sample and reference is measured as a function of temperature in classical DSC, the energy difference between sample and reference is measured as a function of temperature. Hence, DSC is simply quantitative DTA , or more precisely, DSC is a combination of DTA and adiabatic calorimetry. DSC is the more recent technique and was developed for quantitative calorimetric measurements over a wide temperature range from subambient to 1500 C. DTA is not appropriate for such precision measurements and has been progressively replaced by DSC, even for high-temperature measurements, as the major thermal anal-ysis/calorimetric technique. DSC is a differential calorimeter that achieves a continuous power compensation between sample and reference. 

See differential thermal analysis, differential scanning calorimeter, dynamic mechanical analyzer, and thermogravimetric analysis. 

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