3.2.5. Thermal Stability

The thermal stability of ChNF, CNF and their composites were examined by TGA, and the results are shown in Figure 9. At 30 to 100 ◦C of the evaporation stage, there was no significant difference in the first stage of water evaporation in the composites except ChNF. The CNF and their composites started to degrade around 200 ◦C and reached around 320 ◦C for the first phase of degradation, while ChNF started to degrade near 250 ◦C. The composites showed almost the same thermal degradation range as the CNF. It can be seen that they are stable up to 250 ◦C. Note that the CNF and ChNF exhibited larger residuals than the composites. The residuals after 320 ◦C was around 40–50% for CNF and ChNF. The reason for larger residuals of the CNF and ChNF than the composites is under investigation.

**Figure 9.** TGA of ChNF–CNF composites.
