## 3 Results and Discussion
### Tensile Strength
In contrast, the quadratic effect of MDI (C\({}^{2}\)) is not statistically significant (F = 0.3189, \(p\) = 0.5899). In conclusion, the HSO (B) factor is identified as the most influential factor in both models, significantly impacting the mechanical properties of biocomposites. The CPP (A) factor also plays a pivotal role in determining tensile strength and strain, whereas  
Figure 6: Effect of HSO and CPP content on the (**a**) tensile strength and (**b**) strain %. the contribution of the MDI (C) factor is comparatively limited. The effects of binary interactions and the quadratic term of the C factor are found to be negligible. These findings underscore the necessity of meticulous optimization of the HSO and CPP ratios during biocomposite production, as these factors exert pronounced and intricate influences on their mechanical properties. The correlation between the experimental data and the values predicted by the RSM model is illustrated in Figure 7. In all subplots, the alignment of the data points along the first diagonal (45\({}^{\circ}\) inclined) line indicates a high degree of correlation between the experimental results and the model's predicted values. This evidence substantiates the assertion that the RSM model offers consistent and reliable predictions for all analyzed material properties. The statistical analysis results presented in Table 7 demonstrate a high degree of correlation between the experimental data and the values predicted by the RSM model. For all material properties, the coefficient of determination (R\({}^{2}\)) ranges between 0.9896 and 0.9998, while the adjusted R\({}^{2}\) and predicted R\({}^{2}\) values are similarly high, thereby confirming the accuracy and reliability of the model. The low standard deviation and coefficient of variation (C.V. %) indicate that the model is both consistent and stable. It is noteworthy that the error rates for bulk density and thermal conductivity are exceptionally low, which serves to illustrate the precision of the model with respect to these properties. Moreover, the elevated adequate precision values indicate a robust signal-to-noise ratio, substantiating the model's capacity to generate dependable projections. In conclusion, the results demonstrate that the model accurately represents the experimental data and exhibits high predictive performance. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Tensile Strength**} & \multicolumn{4}{c}{**Strain (\%)**} \\ \hline
**Source** &
\begin{tabular}{c} **Sum of** \\ **Squares** \\ \end{tabular} & **Mean Square** & **F-Value** & _p-Value_ & **Sum of Squares** & **Mean Square** & **F-Value** & _p-Value_ \\ \hline
**Model** & 0.6578 & 0.0731 & 74.03 & \textless{}0.0001 & 71,456.42 & 7939.60 & 396.69 & \textless{}0.0001 \\ \hline
**A—CPP (g)** & 0.0082 & 0.0082 & 8.30 & 0.0236 & 13,228.82 & 13,228.82 & 660.96 & \textless{}0.0001 \\ \hline
**B—HSO (g)** & 0.3925 & 0.3925 & 397.53 & \textless{}0.0001 & 46,648.26 & 46,648.26 & 2330.70 & \textless{}0.0001 \\ \hline
**C—MDI (g)** & 0.2304 & 0.2304 & 233.35 & \textless{}0.0001 & 37.21 & 37.21 & 1.86 & 0.2150 \\ \hline
**AB** & 0.0000 & 0.0000 & 0.0000 & 1.0000 & 4675.45 & 4675.45 & 233.60 & \textless{}0.0001 \\ \hline
**AC** & 0.0000 & 0.0000 & 0.0000 & 1.0000 & 0.7200 & 0.7200 & 0.0360 & 0.8550 \\ \hline
**BC** & 0.0000 & 0.0000 & 0.0000 & 1.0000 & 0.7200 & 0.7200 & 0.0360 & 0.8550 \\ \hline
**A\({}^{2}\)** & 0.0007 & 0.0007 & 0.7011 & 0.4301 & 3270.43 & 3270.43 & 163.40 & \textless{}0.0001 \\ \hline
**B\({}^{2}\)** & 0.0240 & 0.0240 & 24.29 & 0.0017 & 4288.19 & 4288.19 & 214.25 & \textless{}0.0001 \\ \hline
**C\({}^{2}\)** & 0.0000 & 0.0000 & 0.0352 & 0.8565 & 6.38 & 6.38 & 0.3189 & 0.5899 \\ \hline
**Residual** & 0.0069 & 0.0010 & & & 140.10 & 20.01 & & \\ \hline
**Lack of Fit** & 0.0069 & 0.0014 & & & 76.60 & 15.32 & 0.4825 & 0.7789 \\ \hline
**Pure Error** & 0.0000 & 0.0000 & & 63.50 & 31.75 & & \\ \hline
**Cor Total** & 0.6648 & & & & 71,596.52 & & & \\ \hline \hline \end{tabular}
\end{table}