## 3 Results
Nevertheless, Td of Ch and CMC components in the nanocomposite is constant at around 290-300 \({}^{\circ}\)C, close to the Tm of Ch and CMC at 270 \({}^{\circ}\)C and 284 \({}^{\circ}\)C, respectively [22; 23]. Finally, the Tg particularly describes the flexibility of the polymer chain in the samples. Specifically, the Ch has a rigid structure [24], and its polymer chain is difficult to stretch. Therefore, the Ch content tends to increase the Tg; with sample A (60 wt% Ch) rendering higher Tg compared to the samples with lower Ch composition, and thus, the trend of Tg is the inverse of the variation of CMC composition. Furthermore, TGA measurements were conducted, to understand the mass changes resulting from applied heating to the samples at 25-900 \({}^{\circ}\)C, as depicted in Figure S2 of the supporting materials. Thus, we show the compilation of the observed data we obtained in TGA measurements in Table 3. We found that mass degradation is divided into four regions of temperature ranges. The first range is at 25-178 \({}^{\circ}\)C, with the mass degradation of 0.36-3.85% occurring in relation to the water steam point, which agrees with DSC measurement. This determines the Tb of the scaffold at 117-178 \({}^{\circ}\)C. The second range, at 178-400 \({}^{\circ}\)C, indicates the decomposition of Ch and CMC of 0.70-14.94%. The third range, 400-660 \({}^{\circ}\)C, indicates decomposition of HA of 0.71-11.05%. The fourth range, at 660-800 \({}^{\circ}\)C, is presumably due to the decomposition of CO\({}_{3}\)\({}^{2-}\) and HPO\({}_{4}\)\({}^{1-}\) in the HA [25]. In general, the percentage of mass degradations decreases with the increase of CMC compositions. We speculate that the CMC reinforces chemical bonding of the scaffold compounds. The functional group of NH3\({}^{+}\) in Ch is strongly connected with the functional group of COO\({}^{-}\) in CMC [26]. Thus, it affects the compound degradation. Figure 5: The variations in steam temperature (Tb), glass transition temperature (Tg), decomposition temperature (Td) (n-HA, Ch and CMC), and crystallization temperature (Tc) of the samples taken from observation of DSC measurements. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Samples**} & \multirow{2}{*}{**Initial Mass**} & \multicolumn{4}{c}{**Mass Degradations (\%)**} & \multicolumn{2}{c}{**Total Mass**} \\  & **(mg)** & **25–178 (\({}^{\circ}\)C)** & **178–400 (\({}^{\circ}\)C)** & **400–660 (\({}^{\circ}\)C)** & **660–800 (\({}^{\circ}\)C)** & **Degradation (\%)** \\ \hline A & 45.67 & 3.85 & 14.94 & 5.39 & 0.93 & 25.12 \\ B & 48.50 & 0.59 & 1.76 & 11.05 & 0.65 & 14.05 \\ C & 61.70 & 0.40 & 1.00 & 1.58 & 0.37 & 3.35 \\ D & 80.74 & 0.36 & 0.70 & 1.11 & - & 2.17 \\ E & 51.00 & 0.52 & 0.82 & 0.71 & - & 2.05 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The changes of scaffold mass, from TGA measurement. We continued the thermal analysis of the samples by using TMA measurements, as depicted in Figure S3 of the supporting materials. Figure 6 depicts a compilation of the observed data we obtained in TMA measurements. It is clear that sample A has the highest shrinkage, due to no CMC content. The scaffold with no CMC is weak when they are mechanically pressed during TMA measurement. These TMA measurements show that CMC has a significant effect on the sample dimension reduction and the mechanical strength of the samples. According to Table 4, the expansion coefficient is divided into four-term temperatures; 25 \({}^{\circ}\)C, 110 \({}^{\circ}\)C, 282 \({}^{\circ}\)C, and 713 \({}^{\circ}\)C. The expansion coefficients at 110 \({}^{\circ}\)C, 282 \({}^{\circ}\)C, and 713 \({}^{\circ}\)C are correlated to water evaporation and degradation of the compound in the samples. Particularly, the expansion coefficient at 25 \({}^{\circ}\)C, which is considered similar to body temperature, tends to decrease with increasing CMC with a constant positive value.