The three
glas transitions, which are not equally well visible for all ABS types, are typical for Acrylonitrile-Butadiene-Styrene Copolymer (ABS). Sometimes, only the
glass transition at 100 to 105 ºC can be seen.
The first
glass transition in the 2nd heating (green curve) with a temperature of approx. -84 ºC can be attributed to the polybutadiene component. The second
glass transition at 106 ºC (2nd heating) can be attributed to the polystyrene component. I contrast to the 1st heating (blue), the
glass transition in the 2nd heating shows a relaxation peak, indicating that the cooling process in the instrument (controlled cooling between the two heatings) was slower than the cooling during production of the granulate. The last and highest
glass transition at 118 ºC (1st heating) is dependent on the acrylonitrile component and - as can be seen in the enlarged scaling - overlaps with the peak in this case.