1. Oxidation Induction Time (OIT) Test for PE, PPR, and Similar Pipe Materials:

The Oxidation Induction Time (OIT) is measured using a Differential Scanning Calorimeter (DSC). The sample is first heated in a nitrogen atmosphere to a specified temperature and held isothermally. Then, the atmosphere is switched to oxygen. After a certain period, the material starts to oxidize and releases heat. This exothermic reaction is detected by the sensor and analyzed via software to determine the OIT value. The length of the OIT reflects the material’s resistance to oxidative degradation. This is a highly meaningful parameter, and for underground plastic piping, OIT testing is usually a mandatory procedure.


2. Glass Transition Test for Resins and Similar Materials:

In amorphous polymers, the process of transitioning from a rubbery (highly elastic) state to a glassy state upon cooling—or from a glassy state to a rubbery state upon heating—is known as the glass transition. The temperature at which this transition occurs is called the glass transition temperature.

For crystalline polymers, the glass transition refers to the transformation occurring in the amorphous regions only, representing the same shift between rubbery and glassy states. Thus, glass transition is a phenomenon commonly observed in polymers. However, it is not limited to polymers—some small-molecule compounds also exhibit glass transition behavior.

3. Melting Point and Enthalpy Test of Materials (Thermal Stability Test):

The melting point is the temperature at which a solid changes its phase from solid to liquid. For multi-component mixtures, multiple melting peaks may be observed.
The enthalpy test is not only used to determine the heat of fusion but is also applicable in evaluating the degree of crystallinity of the material.




4. Curing and Decomposition Exothermic Test for Materials like Adhesives:

This refers to the process in which substances transform from low-molecular-weight compounds into high-molecular-weight polymers. After curing, the resulting samples generally exhibit higher mechanical strength. During the decomposition of the sample, an exothermic effect (heat release) may also be observed.