Applications
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Thermal analysis methods are increasingly used in industrial quality control and research and testing laboratories and can be used to characterise a wide range of materials, including polymers, organic materials, petroleum products, foodstuffs, pharmaceutical compounds, raw mineral products, ceramics, metals and alloys and nuclear compounds. Below is a summary of the main measurement techniques followed by some common applications:

Thermal analysis measurement techniques

Differential thermal analysis (DTA)
Differential scanning calorimetry (DSC)
Calorimetry
Thermogravimetric analysis (TGA)
Thermomechanical analysis (TMA)

 


Common applications of thermal analysis measurement techniques

Temperature and enthalpy of phase change (melting, crystallisation, sublimation, evaporation) (DTA, DSC)

Temperature and enthalpy of transition (first order, second order) (DTA, DSC)

Glass transition (DSC, TMA)

Phase diagram (DTA, DSC)

Temperature and heat of denaturation, gelatinisation, gelation, (DSC, calorimetry)

Dehydration, dehydroxilation, decomposition (DTA, DSC, TGA)

Oxidation, reduction (DSC, TGA)

       

Temperature and enthalpy of transformation, reaction, polymerisation (DSC, calorimetry)

Enthalpy of mixing, dilution, dissolution (calorimetry)

Enthalpy of combustion (calorimetry)

Heat capacity (DSC, calorimetry)

Purity (DSC)

Kinetic parameters (DSC, calorimetry, TGA)

Dilatation coefficient (TMA)

Sintering (TMA)

Adsorption, desorption (DSC, calorimetry, TGA)

           

 


DSC and calorimetry are key methods for investigation of solid pharmaceuticals,
especially for polymorphism characterisation
 
      
TGA and DTA are ideal for investigating materials at high and very high temperature, especially oxide and non-oxide ceramics.

   


DTA is one of the most powerful techniques for determining phase diagrams of binary and ternary mixtures.
        
Bomb calorimetry is the calorimetric technique best suited for measuring the heat content of organic materials, especially fossil fuels.

 

The following table indicates the kind of signal that should be obtained, dependent on the measured properties and the thermal technique used for the investigation. However, note that in some cases (for example reduction or mixing reaction) the calorimetric signal can be either endothermic or exothermic, according to the samples.

Properties DTA
(ΔT, T)

DSC
(T, ΔH)

Calorimetry
(T, ΔH)
TGA
(T, Δm)
TMA
(T, Δl)

Melting

 

Crystallisation, crystallinity

 

 

Evaporation

 

 

Sublimation

 

 

Denaturation

 

 

 

Aggregation

 

 

 

 

Gelation

 

 

 

Gelatinisation

 

 

 

Phase transition

 

Glass transition

 

 

 

Curie Point

 

 

 

Purity

 

 

 

 

Softening

 

 

 

 

Pyrolysis

 

 

 

Dehydration

 

 

 

Dehydroxylation

 

 

 

Decomposition

 

 

Polymerisation, reticulation

 

 

 

Oxidation

 

 

 

Combustion

 

 

 

Reduction

 

 

Dilution, dissolution

 

 

 

 

Hydration

 

 

 

 

Gas adsoption

 

 

 

Gas desorption

 

 

 

Dilatation

 

 

 

 

Sintering

 

 

 

 

Symbols:

 endothermic effect

  exothermic effect

 glass transition

 mass loss

 mass gain

 length increase

 length decrease

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