2.5.3. Dynamic Thermomechanical Analysis (DMA)

The dynamic mechanical properties of the rectangular WPU-SS spline (30 mm × 10 mm) were tested using the tensile mode of the DMA 850 dynamic thermomechanical analyzer of the United States TA company. The test temperature range is −100~120 ◦C, and the experimental frequency is 1 Hz. The heating rate is 5 ◦C/min.

#### 2.5.4. Thermogravimetric Analysis (TGA)

A certain amount of WPU-SS was investigated by the TGA55 thermogravimetric analyzer of TA company. It was carried out in a nitrogen atmosphere with an airflow velocity of 20 mL/min, a heating rate of 10 ◦C/min and a temperature range of 30~800 ◦C.
