## 3 Results and Discussion  
### Characterization of MCC  
The yield of MCC from the cassava pulp is calculated based on the amount of MCC obtained compared to the initial amount of cassava pulp used. In this study, the MCC yield is given as 14.92%. This is higher than the extraction of MCC from cassava pulp in previous research, MCC yield of 7.20% [25]. The FTIR spectra of cassava pulp and MCC are shown in Figure 1a. Both cassava pulp and MCC samples represented -OH stretching at peaks between 3600 and 3000 cm\({}^{-1}\). This band was associated with cellulose's intermolecular hydrogen bonding [28; 29]. The FTIR peaks of cassava pulp and MCC at 898 cm\({}^{-1}\), 1204 cm\({}^{-1}\), and 1318 cm\({}^{-1}\) were assigned as beta glycosidic linkages of the glucose ring, OH deformation, and CH\({}_{2}\) wag. These bands were related to the cellulose components's structure [30; 31]. C=O stretching and C=C aromatic ring, which are related to lignin and hemicellulose, were represented by the peaks of cassava pulp at 1732 cm\({}^{-1}\) and 1505 cm\({}^{-1}\), respectively [30; 31]. These peaks clearly disappeared in the MCC, showing that hemicelluloses and lignin were partially removed from the fiber structure, resulting in increased cellulose purity. In Figure 1b, the XRD curve illustrates distinct crystalline peaks at 20 values of 16\({}^{\circ}\) and 22\({}^{\circ}\) for both cassava pulp and MCC. Notably, the crystalline peak of MCC displays a higher intensity compared to that of cassava pulp. The calculation of the crystallinity index (CrI) for all samples is depicted in Table 2. MCC demonstrates a notably high crystallinity of 47%, attributed to the removal of hemicelluloses and lignin bound to the cellulose fibers. Conversely, cassava pulp exhibits the lowest CrI at 19%. Thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG) are techniques used to study the thermal stability and decomposition behavior of materials. These curves provide insights into how a material's weight changes as it is heated over time, \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sample** & \begin{tabular}{c} **Amorphous Region** \\ **Feak Intensity (a.u.)** \\ \end{tabular} & \
\begin{tabular}{c} **Crystalline Region** \\ **Feak Intensity (a.u.)** \\ \end{tabular} &
\begin{tabular}{c} **CrI (\%)** \\ \end{tabular} \\ \hline Cassava pulp & 5441 & 6725 & 19.10 \\ MCC & 5070 & 9550 & 46.91 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The crystallinity index (CrI) of cassava pulp and MCC. Figure 1: (**a**) FTIR spectra and (**b**) XRD spectra of cassava pulp and MCC. and DTG gives the rate of weight loss at each temperature. The TGA and derivative thermogravimetry (DTG) curves of cassava pulp and MCC are shown in Figure 2a,b. Both cassava pulp and MCC experience weight loss below 100 \({}^{\circ}\)C due to moisture evaporation. This is typical for many organic materials, as they often contain some level of moisture that evaporates when heated. The maximum thermal decomposition temperature is the temperature at which the material experiences its highest rate of decomposition. For cassava pulp, this temperature is 312 \({}^{\circ}\)C, while for MCC, it is 343 \({}^{\circ}\)C. This indicates that MCC has higher thermal stability compared to cassava pulp because it can withstand higher temperatures before undergoing significant decomposition. The higher thermal stability of MCC compared to cassava pulp suggests that MCC is more resistant to thermal degradation. This could be attributed to differences in chemical composition. For example, MCC is predominantly composed of cellulose, which has a high thermal stability compared to other components found in cassava pulp, such as hemicellulose, lignin, pectin, starch, and lipid [32]. The mention of alkali treatment and bleaching implies that cassava pulp undergoes a chemical treatment process to remove certain components and improve its properties.