Testing methods of Melting Point (Tm)

The testing method of Melting Point (Tm) our factory uses is a microscope with a Thermal Optical Microscope (TOM), which combines optical microscopy and thermal analysis techniques to observe the melting behavior of materials during heating. The specific steps are as follows:

1. Sample Preparation:

1. • Select a representative polyester chip sample, ensuring it has a smooth surface and appropriate size.
   • Place the polyester chip on the stage of the thermal optical microscope.

2. Set Temperature Program:

1. • Start the thermal optical microscope and set the heating rate, typically 5-10°C/min.
   • Set the appropriate temperature range, generally within the expected melting point of the polyester sample.

3. Heating Process:

1. • Begin heating the sample while observing its surface changes through the microscope.
   • Polyester will show significant phase transition characteristics when approaching its melting point, such as the surface starting to soften or form a molten zone.

4. Observe Melting Behavior:

1. • Observe the sample’s morphology under the microscope. Typically, when the surface shows clear signs of melting or a liquid phase, it indicates the polyester has reached its melting point.
   • Record the temperature at which the surface change occurs, which is the melting point of the polyester.