用户通讯

Thermal Analysis UserCom 2

用户通讯

UserComs Are Biannual Application Journals Intended for All Users of Thermal Analysis

Thermal Analysis UserCom 2
Thermal Analysis UserCom 2

Table of Contents:

TA Tip

  • Selection of the heating rate

New in the sales program

  • New DSC821e module
  • New cooling option (intra cooler)
  • Automatic crucible opening before the measurement

Applications

  • New possibilities with ADSC
  • cp measurement with TGA/SDTA
  • Curing behavior of adhesives

New possibilities with ADSC cp

TGA850 specific heat from the SDTA curve?

Several users have asked us whether at least a semiquantitative measurement of the specific heat from the SDTA signal is possible. As the temperature function of the calorimetric sensitivity is not (yet) known, only the sapphire crucible method can be used. As the cp temperature function of sapphire is known, use is made of a standardization employing a sapphire measurement corrected by the blank curve. The software used the rule of three to calculate the specific heat from the sample measurement corrected by the blank curve:

cp = cpSap • mSap • SDTAProbe /(mProbe • SDTASap)

[…]

Measurement with TGA/SDTA

Alternating differential scanning calorimetry, ADSC, opens up new possibilities

In DSC, the heat flow of the sample under investigation is usually measured at a constant heating or cooling rate. High heating and cooling rates – 10 K/min and higher – have the advantage of high measurement sensitivity (large peak), however, this is associated with low resolution relative to the temperature axis. At low rates, on the other hand, the conditions are the opposite: virtually invisibly small peaks which are often very well separated. ADSC with its periodic temperature program combines the advantages of both measurement modes: – High sensitivity thanks to high instantaneous heating rate – High temperature resolution thanks to low average heating rate

[…]

Curing behavior of adhesives

Model-free kinetics

The launch of the new software version also saw the introduction of the model-free kinetics in the last issue of User Com. As numerous measurements have shown, in most cases these new model-free kinetics allow a considerably more accurate prediction than the traditional model concepts, even in the case of complex or multi-stage reactions.

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