Development and characterization of post-consumer diaper waste reinforced epoxy composite: A circular economy approach to municipal solid waste management

With an annual production exceeding 48 million tons, disposable diapers pose a significant environmental challenge. This study presents an approach for converting sterilized diaper waste into reinforcement for epoxy composites. Diapers were sterilized using chemical treatment with hydrogen peroxide and ethanol, followed by autoclaving at 134 °C and 20 psi. The absorbent core containing fluff pulp and superabsorbent polymers was incorporated into epoxy resin at 10, 15, 20, and 25 wt%. Mechanical properties were evaluated by tensile, flexural, impact, and hardness tests, while density and water absorption were also measured according to ASTM standards. Morphological and elemental analyses were conducted using SEM and EDS. Mechanical performance improved markedly with increasing reinforcement content. Tensile strength increased from 13.1 MPa to 24.6 MPa, flexural strength from 2.08 MPa to 29.2 MPa, impact strength from 4.17 kJ/m 2 to 20.83 kJ/m 2 , and Shore D hardness from 75 to 93. Density ranged from 1.63 to 1.71 g/cm 3 , and water absorption increased from 4.22% to 9.33%. SEM images showed improved reinforcement dispersion and mixed failure modes at higher loadings, while EDS confirmed a carbon- and oxygen-rich composition, free of hazardous inorganic contaminants. The results demonstrate the feasibility of using sterilized diaper waste as reinforcement in non-load-bearing, moisture-stable epoxy composites, supporting waste valorization within a circular economy framework.