## 3 Results and Discussion  
### TGA Analysis  
The thermal stability of the film composites was assessed using thermogravimetric analysis (TGA) and derivative thermogravimetric analysis (dTG) graphs, as shown in Figure 3. The parameters of thermal decomposition are summarized in Table 1.  
The thermal degradation pattern of pure PW, the sodium alginate-modified compounds, and the crosslinked samples exhibited similar overall trends. All samples displayed two distinct weight loss stages occurring at 50-150 \({}^{\circ}\)C and 200-350 \({}^{\circ}\)C. The first weight loss stage (Stage I) is primarily attributed to the evaporation of moisture, resulting from the hydrophilic properties of both PW and SA. A clear difference was observed between PAlv and PAhv composites. The weight loss for PAlv in the 50-150 \({}^{\circ}\)C range was 15%, while for PAhv, it was 8.5%. This difference is due to the varying water retention capacities of SA with different viscosities. Low-viscosity SA has a lower moisture retention capacity, leading to quicker moisture loss in dry conditions or faster moisture  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multicolumn{2}{c}{**Stage I (50–150 \({}^{\circ}\)C)**} & \multicolumn{2}{c}{**Stage II (200–350 \({}^{\circ}\)C)**} \\  & **Tg (\({}^{\circ}\)C)** & **Am (\%)** & **Decomposition Temperatures (\({}^{\circ}\)C)** & **Am (\%)** \\ \hline Pure PW & 60 \(\pm\) 2 & 11 \(\pm\) 0.8 & 290 \(\pm\) 1 & 62 \(\pm\) 1.4 \\ PAlv & 48 \(\pm\) 5 & 15 \(\pm\) 1.1 & 225 \(\pm\) 1; 275 \(\pm\) 1 & 57 \(\pm\) 0.5 \\ PAlvx & 45 \(\pm\) 5 & 16 \(\pm\) 1 & 230 \(\pm\) 2; 280 \(\pm\) 1 & 55 \(\pm\) 0.3 \\ PAhv & 38 \(\pm\) 4 & 8.5 \(\pm\) 1.4 & 220 \(\pm\) 2; 270 \(\pm\) 1 & 60 \(\pm\) 2.8 \\ PAhvx & 30 \(\pm\) 3 & 8.5 \(\pm\) 1.2 & 240 \(\pm\) 1; 290 \(\pm\) 1 & 60 \(\pm\) 1.5 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Summary of thermal properties: Tg, TGA weight loss (\(\Delta\)m) for two major stages, and decomposition temperatures.  
Figure 3: (**a**) TGA and (**b**) DTG curves of PW, PW/SA (PAlv, PAhv), and crosslinked PW/SA films (PAlvx, PAhvx).  
uptake in humid environments [36]. In contrast, high-viscosity SA forms stronger polymer networks in hydrogel structures, allowing it to retain moisture for longer periods [37]. The next major degradation stage (Stage II) occurs within 200-350 \({}^{\circ}\)C and corresponds to the decomposition of polysaccharides, which are the primary components of both potato waste and sodium alginate [38]. The total mass degradation in this temperature range was between 55 and 60% across all formulations, including pure PW, binary composites, and their crosslinked variants.  
The incorporation of SA into the PW resulted in lower thermal stability, regardless of its viscosity. The pure PW film exhibited a single degradation peak at around 290 \({}^{\circ}\)C. However, after the incorporation of SA, a new peak emerged at around 225 \({}^{\circ}\)C, corresponding to the thermal breakdown of SA. This observation aligns with the findings reported by [PERSON] et al. [39]. The primary degradation peak for the PW component remained at 290 \({}^{\circ}\)C, which is consistent with the decomposition temperatures of starch (280 \({}^{\circ}\)C) [40] and cellulose (300 \({}^{\circ}\)C) [41], the major subcomponents of PW.  
Crosslinking had different effects on PAlv and PAhv composites. In PAlv composites, crosslinking did not cause a noticeable impact on thermal degradation behavior. However, for PAhv composites, crosslinking led to a notable shift toward higher temperatures. In the PAhv composite, thermal degradation occurred at 220 \({}^{\circ}\)C and 270 \({}^{\circ}\)C, whereas after crosslinking, the maximum degradation temperatures in PAhvx increased to 240 \({}^{\circ}\)C and 290 \({}^{\circ}\)C. This shift suggests that crosslinking enhances the thermal stability of composites containing hvSA by reinforcing polymer interactions, thereby delaying thermal decomposition.