3.2.6. UV Transmittance

UV protection of ChNF–CNF composites is an important factor for food packaging applications. UV transmission of the composites was evaluated, and the results are shown in Figure 10. As compared to the neat CNF, the ChNF–CNF composites showed better UV-protection. Higher CTS content showed better the UV protection. In the range of UV-A, UV-B, and UV-C, CTS10, CTS15 and CTS20 exhibited higher UV protection than CTS3, CTS5 and CTS7. However, transparency of the composites is sacrificed to improve the UV protection. Thus, good UV protection with maintaining good transparency is future work.

**Figure 10.** UV-transmittance of ChNF–CNF composites.
