Perkin-Elmer calorimeter

The theory of the Perkin-Elmer calorimeter has been presented by O Neil (129), Gray (60), and Flynn (134), while that of the DuPont and Stone instruments has been discussed by Baxter (130) and David (131), respectively. The theory of the latter two instruments has been discussed previously in this chapter. 

Middle point of the corresponding heat capacity jump measured at a heating rate of lOC/min on a Perkin-Elmer calorimeter. 

The melting points reported in Table II were recorded at the end of the melting process, made at a heating rate of 40 K/min, on a DSC-IB Perkin-Elmer calorimeter for samples prepared by isothermal crystallization at 273 K, during 4 h. 

Differential Scanning Calorimeter (DSC) thermograms were obtained on a Perkin Elmer DSC-2 run at 10°C per minutes. Dynamic Mechanical Thermal Analysis (DMTA) spectra were obtained on a Polymer Labs DMTA at a frequency of 1Hz with a temperature range from -150°C to +150°C at a scan rate of 5°C per minute. 

Thermal Analysis - Differential Scanning Calorimetry (DSC) and thermal gravimetric analysis (TGA) were used to characterize the thermal properties of the polymers synthesized. DSC analysis was performed on a Perkin-Elmer Differential Scanning Calorimeter, Model 2C with a thermal analysis data station. Thermal gravimetric analysis (TGA) was carried out on a DuPont thermal gravimeter, Model 951. From the DSC and TGA plots of poly (N-pheny 1-3,4-dimethylene-... 

Safety studies of the graphite anode samples were performed using a Perkin-Elmer Differential Scanning Calorimeter (DSC, model Pyris 1) instrument. The temperature scanning rate was 10 C/min over a temperature range of 50 to 375°C. 

The DSC curve of pseudoephedrine hydrochloride obtained with a Perkin Elmer DSC-1B differential scanning calorimeter is shown in Figure 5.7 The heating rate was 5°C/min. The heat of fusion is 6.4 Kcal/mol. The melting point (uncorrected) is 184°C. 

Glass transition temperatures of the uv-hardened films were measured with a Perkin Elmer Model DSC-4 differential scanning calorimeter (DSC) that was calibrated with an indium standard. The films were scraped from silicon substrates and placed in DSC sample pans. Temperature scans were run from -40 to 100-200 °C at a rate of 20 ° C/min and the temperature at the midpoint of the transition was assigned to Tg. 

O Neill M. J. and Fyans R. L. (1971). Design of differential scanning calorimeters and the performance of a new system. Norwalk, Connecticut, Perkin-Elmer Corp., 38 pp. 

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... 

Glass transition temperature (Tg) measurements were carried out on a Perkin Elmer DSC2 differential scanning calorimeter. A heating rate of 10°C/min was used with the Tg being taken as the midpoint of the temperature interval over which the discontinuity took place (75). 

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. 

Figure 9. Scans of synthetic phospholipids in water taken with a Perkin-Elmer DSC IB differential scanning calorimeter. Lipid concentrations were 10-15% by weight...

Fig. 22. Scanning differential calorimeter trace of heating (top) and cooling (bottom) of a melt crystallized trans-1,4-polybutadiene (Drawn after Ref.14S), Perkin-Elmer DSC, unspecified heating and cooling rates)...

NMR spectra were taken in deuteriochloroform solution, using a Varian HA100 spectrometer. Thermal measurements were made with a Perkin-Elmer DSC IB differential scanning calorimeter at 40°C/min. Near-infrared spectra were measured in carbon disulfide solution with a Beckman DK 2A spectrophotometer. Gas-chromatographic analyses of reaction mixtures were carried out after conversion of the phenols to trimethylsilyl ethers by reaction with bis (trimethylsilyl) acetamide. 

Calorimetric measurements were made using a Perkin-Elmer DSC-1B differential scanning calorimeter. A uniform heating rate of 10 °C per minute was employed for all measurements. 

In the CSM laboratory, Rueff et al. (1988) used a Perkin-Elmer differential scanning calorimeter (DSC-2), with sample containers modified for high pressure, to obtain methane hydrate heat capacity (245-259 K) and heat of dissociation (285 K), which were accurate to within 20%. Rueff (1985) was able to analyze his data to account for the portion of the sample that was ice, in an extension of work done earlier (Rueff and Sloan, 1985) to measure the thermal properties of hydrates in sediments. At Rice University, Lievois (1987) developed a twin-cell heat flux calorimeter and made AH measurements at 278.15 and 283.15 K to within 2.6%. More recently, at CSM a method was developed using the Setaram high pressure (heat-flux) micro-DSC VII (Gupta, 2007) to determine the heat capacity and heats of dissociation of methane hydrate at 277-283 K and at pressures of 5-20 MPa to within 2%. See Section 6.3.2 for gas hydrate heat capacity and heats of dissociation data. Figure 6.6 shows a schematic of the heat flux DSC system. In heat flux DSC, the heat flow necessary to achieve a zero temperature difference between the reference and sample cells is measured through the thermocouples linked to each of the cells. For more details on the principles of calorimetry the reader is referred to Hohne et al. (2003) and Brown (1998). 

The thermal properties of the polymers reported in Table A.2 and Table A.3 were obtained by using a Perkin-Elmer Differential Scanning Calorimeter Model DSC-7 using a heating rate of 20°C/min. The specific heat was obtained using a heating rate of 10°C/min. For semicrystalline material, the heat of fusion was obtained from the measured specific heat curves. The crystallization temperature was obtained at 20°C/min cooling rate. 

Differential Scanning Calorimetry (DSC) Studies. Hairless mouse abdomen stratum corneum, extracted lipids and protein residues were studied with a Perkin Elmer 4 differential scanning calorimeter (DSC) equipped with a thermal analysis data system (TADS). Scanning rates were 10°C per minute over the temperature region -10 to 237°C. Stratum corneum, extracted lipid and protein residue samples obtained from the abdomen of the hairless mice (average 10 mg/sample) were studied in the desiccated state following evaporation of any residue water or solvents by vacuum drying at 10 4 Torr. 

Glass temperatures have been determined by the DTA method with two different instruments (a Mettler differential thermoanalyzer and a Perkin-Elmer differential scanning calorimeter DSC 1) (9) in two different laboratories. They are listed in the two last columns of Table I. Small differences of 0°—7°C. were observed. This order of agreement was sufficient. 

A Perkin-Elmer DSC-2 differential scanning calorimeter equipped with an Automatic Scanning Zero was used. DSC conditions were 20 K/min on a 20.8-mW sensitivity with a 24-mg aluminum reference. 

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