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Thermal

Differential Scanning Calorimetry (DSC) polymer analysis and plastic analysis measures the heat capacity of a sample.

This measurement is rich in information content because it reveals the thermal transitions that occur within the sample.  The transitions include residual reactivity, evaporation of solvents, melting, crystallization, crystal transitions, and glass transition temperature.

Approaches

Differential Scanning Calorimetry (DSC) analysis can be performed from -90 to 725 °C and although the ambient atmosphere is usually nitrogen, that can be altered for specific analytical protocols. 

The rate at which the sample can be heated and cooled is controlled and often set to 10 °C per minute.  However, samples can also be rapidly cooled (quench cooled) for specific analytical purposes.

Although the release of solvent can be determined using a DSC, this technique is not the best option for that.  Thermogravimetric Analysis is a better choice TGA. 

ASTM Standards:

  • D3418 (Tg & Tm)
  • E1952 (thermal conductivity by MDSC)
  • E1269 (heat capacity by MDSC)
  • E794 (melting and crystallization temperatures)
  • D3895 (oxidative induction time, OIT)

Sample Considerations

Virtually all plastic and rubber materials are evaluated using Differential Scanning Calorimetry.  In addition, some inorganic materials and shape memory alloys can be characterized using the DSC instrument.

Samples are typically solid when evaluated by the Differential Scanning Calorimeter. Liquid samples can also be tested.

A typical polymer sample weighs about 10 milligrams and metal samples can be up to about 40 milligrams due to their higher densities. 

From a size perspective, a “perfect DSC sample” is a quarter inch diameter disk approximately 1 mm thick. 

It is also preferred that the sample remain in the sample pan so special considerations are required if the sample can foam during the heating cycles. 

Contact an expert to talk through your specific sample considerations.  

Experience

Work we’ve done:

  • Determination of cure in fiberglass reinforced epoxy products
  • Heat capacity of ceramic disks
  • Crystallization kinetics of a polymer

Products we’ve tested:

  • Melt spun fiber products
  • Injection molded plastic
  • Medical devices