Discarded custard apple seed powder waste-based polymer composites: an experimental study on mechanical, acoustic, thermal and moisture properties

This study focuses on developing hybrid composite materials using natural fibers, including jute fiber (JF), snake grass fiber (SGF), and kenaf fiber (KF), combined with an organic filler, custard apple seed powder (CASP). This study aimed to evaluate the mechanical properties, sound absorption, thermal behavior, and water absorption behavior of the developed composite materials. The best results were obtained for the composite material (sample C), which contained 5% jute fiber, 8.75% snake grass and kenaf fiber, 7.5% CASP, and 70% epoxy resin, and demonstrated the highest tensile strength (60.43 MPa), impact strength (2.67 J), and compressive strength (48.31 MPa). In contrast, sample D, which contained 10% CASP, exhibited the best flexural strength (145.51 MPa) and interlaminar shear stress (2.26 MPa). Thermal studies revealed that the sample with 7.5% CASP degraded at 280 °C and remained stable until 600 °C, indicating that it had a greater thermal stability than the other samples. The addition of CASP to natural fibers improved sound absorption by increasing the density and porosity of the composite material. The water absorption results confirmed that sample C exhibited better resistance to water absorption than the other samples. Microscopic analysis revealed the failure mode and interfacial bonding between the matrix, fiber, and filler. The findings suggest that the developed materials can be used as sound-resisting materials in various applications, such as automotive components and theatre interiors. This study demonstrates the potential of hybrid composite materials made from natural fibers and organic fillers for various engineering applications, offering an environmentally friendly alternative to synthetic composites. Investigations have explored the performance of these materials in different environments and in multidisciplinary applications.