Novel Glass Fiber Composites Reinforced with Date Seed-Derived Carbon for High-Performance Submarine Hulls

This study examines glass fiber-reinforced polyester composites enhanced with carbon derived from date seeds as potential materials for submarine hull construction. Mechanical, physical, and microstructural properties were evaluated through tensile, flexural, compression, impact, density, and water absorption tests. Composites containing 0.5–2.0 wt% carbon were fabricated and assessed under varied loading and environmental conditions. Results show that the 0.5% carbon composite achieved the highest impact toughness (0.137 J) and flexural modulus (95,639.879 MPa), indicating superior resistance to dynamic and bending stresses. The 2.0% carbon composite recorded the greatest tensile strength (4,844.308 MPa) but lower flexibility, whereas the 1.0% carbon composite displayed the lowest density (0.97 g/cm³), enhancing buoyancy for marine use. All samples exhibited 0% water absorption, confirming excellent moisture resistance. SEM–EDS analysis revealed uniform reinforcement dispersion and strong interfacial bonding, particularly in the 0.5% hybrid composite. Overall, the findings highlight date seed–derived carbon as a sustainable reinforcement capable of improving the strength-to-weight ratio of glass fiber composites. It offers a lightweight, corrosion-resistant alternative to conventional metals for submarine structures, warranting further optimization and field testing for marine deployment.