Temperature memory effect in differential scanning calorimeter test in thermoplastic polyurethane

The temperature memory effect (TME) in differential scanning calorimeter test of a thermoplastic polyurethane is investigated in two ways: one is termed TME1, in which the material is cooled down for full crystallization during thermal cycling; while the other is termed TME2, in which the material is cooled, but before any crystallization occurs. In the case of single heating stop temperature (T s ), for TME1, the temperature gap (△T) is almost a constant; while for TME2, △T roughly increases in a linear manner with the increase of T s . We also extend the study to multiple heating stops (upon to four stops) in TME2. It is confirmed that a higher heating stop temperature is able to eliminate the influence of the previous heating cycles if their corresponding heating stop temperature is lower. It is concluded that in all tests (for both TME1 and TME2), △T may be estimated as T s + 1.6 °C with an accuracy of about ±0.5 °C or 4.1 %. A schematic sketch to reveal the origin of △T is presented.