Investigations on Ananas erectifolius fiber/sawdust hybrid epoxy composites for sustainable building applications

This study investigates the mechanical, thermal, morphological, antibacterial, and water absorption characteristics of Ananas erectifolius fiber (AEF) reinforced epoxy composites filled with sawdust particulates, aiming to develop sustainable alternatives to conventional construction materials. Composites were fabricated using the hand layup method followed by compression molding, incorporating sawdust filler contents ranging from 0 to 24 g while keeping the fiber mass constant at 300 g. The composite containing 18 g of sawdust (Sample C3) demonstrated superior overall performance, achieving a tensile strength of 51.09 MPa, flexural strength of 54.98 MPa, impact strength of 14.98 kJ/m², and a Shore D hardness of 51. SEM analysis confirmed strong fiber-matrix interfacial bonding and uniform filler dispersion in the optimized formulation. Thermal assessments showed that Sample C3 exhibited the lowest thermal conductivity (0.72 W/mK), a reduced coefficient of linear thermal expansion (62.1 × 10⁻⁶/°C), and the highest heat deflection temperature (123 °C). TGA revealed enhanced thermal stability, with ~ 18% residual mass at 600 °C. Antibacterial testing against E. coli produced a 26 mm inhibition zone at 100 µg concentration. The water absorption rate remained low at 5.99%, indicating good dimensional stability. The novelty of this work lies in the Integrated valorization of two underutilized bio-wastes Ananas erectifolius fiber and sawdust to engineer a high-performance, eco-friendly hybrid composite tailored for sustainable building applications.