Gamma irradiation effects on mechanical and environmental performance of Al2O3-TiO2 reinforced jute-glass hybrid composites

The development of sustainable, high-performance polymer composites is crucial for structural applications that require both lightweight and environmental durability. This study investigates jute-glass fiber hybrid composites fabricated with epoxy and polyester matrices, reinforced with Al 2 O 3 and TiO 2 nanofillers (0–15 wt%) and post-processed using gamma irradiation (6 kGy). The mechanical properties, water absorption, and environmental degradation under soil burial were systematically evaluated. Mechanical testing revealed that the incorporation of nanofillers substantially enhanced the composite properties, with optimum performance observed at a 10 wt% filler loading. In epoxy-based composites, tensile strength increased from 122.6 MPa (unfilled) to 146.6 MPa at 10 wt% loading, representing a 19.6 % improvement, while elongation at break increased from 10.9 % to 13.1 %. Similarly, impact strength improved from 372.8 to 402.9 kJ/m² (8.1 % increase) at the same filler content. Polyester composites exhibited parallel trends, although overall performance remained lower, with a maximum tensile strength of 102.8 MPa at 10 wt% loading (10.1 % improvement). Gamma irradiation further enhanced the mechanical properties, with irradiated epoxy composites achieving a tensile strength up to 156.4 MPa and irradiated polyester composites reaching 109.7 MPa, indicating improved cross-linking and filler–matrix adhesion. Soil burial tests highlighted degradation effects, with tensile strength reductions of 21.5 % in epoxy (from 122.6 to 96.2 MPa) and ∼20 % in polyester (from 93.4 to 74.8 MPa) after four weeks. Notably, gamma irradiation mitigated these losses, as the irradiated epoxy retained 142.6 MPa compared to 135.9 MPa in non-irradiated samples, while the irradiated polyester maintained 98.5 MPa compared to 94.4 MPa. SEM analysis confirmed improved interfacial bonding and reduced micro-voids in epoxy systems, while polyester composites exhibited more fiber pull-outs and voids, correlating with their lower performance. These findings highlight the synergistic role of ceramic nanofillers and gamma irradiation in producing mechanically robust, moisture-resistant, and environmentally resilient bio-hybrid composites, which are suitable for structural applications in the transportation, marine, and construction sectors.