This study presents a hybrid EOA-FSNN approach for predicting mechanical properties of borophene-reinforced polymer nanocomposites fabricated via fused deposition modeling (FDM). The EOA algorithm optimizes polymer rheological features, while FSNN predicts tensile strength and other mechanical parameters. The method outperforms existing approaches (PCE, ANN, GA), achieving 33 MPa tensile strength and 0.318 MSE, providing a reliable predictive framework for polymer engineering and mechanical property optimization of nanocomposites.