Journal of thermal analysis

, Volume 50, Issue 5–6, pp 727–744 | Cite as

Modulated Differential Scanning Calorimetry

The effect of experimental variables
  • F. Cser
  • F. Rasoul
  • E. Kosior
Article

Abstract

The reproducibility and reliability of the TA Instruments Modulated Differential Scanning Calorimeter (MDSC) was tested over a range of conditions. The equipment base line was found to be fairly constant with a very small fluctuation (10 μW), which means a 0.1 % fluctuation on the scale of a normal polymer MDSC curve. The excellent stability of the base line and the reasonable reproducibility of the curves (5%) suggest that frequent calibration is not required.

The heat capacities calculated from the modulated response to the variable temperature depend on the frequency for a given cell constant. The heat capacity cell constant is a unique function of the modulation frequency:k c =K c o p/(p−6.3) wherep is the time of the periodicity expressed in seconds and K c o is the heat capacity cell constant measured on a standard material and reduced to zero frequency. The cell constants depend on the flow rate of the helium according to:K(He)=K o(1.298−0.004424He+1.438·10−5 He 2) whereHe is the flow rate of helium in ml min−1 andK o represents a constant at 100 cm3 min−1. There is a strong dependence of cell constant on the flow rate ranges from 10 to 80 cm3 min−1, while above this rate (up to 135 ml min−1) the cell constant approaches a plateau.

Keywords

frequency dependence heat capacity MDSC thermal analyses 

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Copyright information

© Wiley Heyden Ltd., Chichester and Akadémiai Kiadó, Budapest 1997

Authors and Affiliations

  • F. Cser
    • 1
    • 2
  • F. Rasoul
    • 1
    • 2
  • E. Kosior
    • 1
    • 2
  1. 1.CRC for Polymers Pty. Ltd.Notting Hill
  2. 2.Polymer Technology CentreRoyal Melbourne Institute of TechnologyMelbourneAustralia

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