Determination of Arrhenius kinetic constants by differential scanning calorimetry

Torfs, J. C. M.; Deij, Leen.; Dorrepaal, Anthonie J.; Heijens, Josef C.

doi:10.1021/ac00278a054

Cited by 44 publications

(23 citation statements)

References 12 publications

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“…This approach has been studied by Kerc' et al (1991), who describe two main methods for obtaining kinetic data from the exotherm. The heat evolution method (Caroll and Manche, 1972;Torfs et al, 1984) involves the measurement of the rate constant k at any temperature during the crystallisation process via:…”

Section: The Physical Stability Of Amorphous Drugsmentioning

confidence: 99%

The relevance of the amorphous state to pharmaceutical dosage forms: glassy drugs and freeze dried systems

Craig

1999

International Journal of Pharmaceutics

416

204

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Section: The Physical Stability Of Amorphous Drugsmentioning

confidence: 99%

The relevance of the amorphous state to pharmaceutical dosage forms: glassy drugs and freeze dried systems

Craig

1999

International Journal of Pharmaceutics

416

204

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“…Hence, protein denaturation can be studied by thermoanalytical techniques such as differential scanning calorimetry (DSC). The kinetics of thermal denaturation can also be studied by various DSC procedures, and the heat evolution method of Borchardt and Daniels (1957) was preferred by many workers for its simplicity and high accuracy (Torfs et al, 1984). The thermal characteristics of oat globulin, the major oat protein fraction, was studied by DSC under different conditions of pH, ionic strength and structure perturbants, and the results suggest the involvement of hydrophobic interaction in the thermal stability of oat globulin .…”

Section: Introductionmentioning

confidence: 99%

Studies of Thermal Denaturation of Oat Globulin by Differential Scanning Calorimetry

Harwalkar

1988

Journal of Food Science

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Heat treatmentsThermal denaturation of oat globulin was studied by differential scanning calorimetry (DSC). Prior heat treatments at 100°C and 110°C resulted in a progressive decrease in enthalpy (AH) indicating partial denaturation. Marked increase in denaturation temperature (Td) and onset temperature (T,) and decrease in width at half peak height (ATr,,) suggest that the preheated protein assumed a more compact conformation or associated to a complex structure with higher thermal stability and cooperativity. The heated globulin was segregated into soluble and insoluble fractions containing native and denatured protein respectively. The denaturation kinetics of oat globulin was studied and results show a reaction order of 2.5 and an activation energy of 505 KJ/mol. Heat treatments caused a pronounced increase in activation energy and pre-exponential factor.Oat globulin was heated at either 100°C or 110°C in O.OlM phosphate buffer (pH 7.4) containing l.OM NaCI. The temperatures and buffer were chosen such that the results can be compared directly with previous data on thermal coagulation of oat globulin . One milligram (2 0.05 mg) freeze-dried protein was weighed to polymer-coated DSC pan (DuPont Co., Wilmington, DE) and 10 )LL buffer were added without mixing. The pan was sealed with a lid and heated on the reference or sample platform of a DuPont DSC high pressure cell preset at 100" or 110°C. Since the sample size (1 mg protein in 10 pL buffer) was small and the solids were evenly distributed on the bottom of the pan, the lags between recorded and actual sample temperatures should be small. After heating for the prescribed time, the pan was cooled rapidly in an ice bath, and reequilibrated to room temperature.

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“…The polymerization was initiated by tert-butyl peroxide (TBPO) because its half-lifetime is about 1 h at 150 8C. [19] The total time of polymerization was set to 5 h for all reactions in regular solvents as well as supercritical fluids. The results are presented in Table 2.…”

Section: Solution Polymerization Of Styrene In 135-trimethylbenzenementioning

confidence: 99%

“…Rate constant of decomposition for the initiator: k d = 2 N 10 -4 s -1 (calculated from k d (s -1 ) = 6.47 N 10 15 e À 158 N 10 3 RT determined in toluene in ref. [19] ) Rate constant for initiation by thermal polymerization:…”

Section: Solution Polymerization Of Styrene In 135-trimethylbenzenementioning

confidence: 99%

Free-Radical Polymerization of Styrene in CO2 /Ethanol Mixed Supercritical Fluid

Mingotaud¹,

Begue

Cansell

et al. 2001

Macromol. Chem. Phys.

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The free‐radical polymerization of styrene has been studied in CO2/ethanol mixed supercritical fluid. Depending on the experimental conditions, yields varied from low to fairly good (around 60%). The polymers exhibited molar masses ranging from 5 000 to 26 000 g/mol. The results obtained were compared with those generated in the presence of mesitylene or pure ethanol used as solvent. In particular, it was observed that the thermal polymerization of styrene in the supercritical fluids or in ethanol was somewhat inhibited as compared to that occurring in mesitylene. Indeed, almost no thermal polymerization could be observed in these conditions.

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Determination of Arrhenius kinetic constants by differential scanning calorimetry

Cited by 44 publications

References 12 publications

The relevance of the amorphous state to pharmaceutical dosage forms: glassy drugs and freeze dried systems

The relevance of the amorphous state to pharmaceutical dosage forms: glassy drugs and freeze dried systems

Studies of Thermal Denaturation of Oat Globulin by Differential Scanning Calorimetry

Free-Radical Polymerization of Styrene in CO2 /Ethanol Mixed Supercritical Fluid

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