Thermo-mechanical and environmental assessment of betel nut-glass fiber ecofriendly laminates: A sustainable solution for structural applications

This study investigates the development and performance of hand lay-up fabricated hybrid composites using chemically treated betel nut fiber (BNF) and glass fiber (GF) reinforced unsaturated polyester resin (UPR) for potential structural applications. A series of laminates with varying BNF content (2–8 wt%) and 6 wt% GF were evaluated to understand the physico-mechanical, thermal, and environmental properties. Incorporation of BNF made the laminates lightweight for structural use. The composite containing 2 wt% BNF exhibited the most balanced performance, achieving the highest tensile (43.26 MPa), flexural strength (110.15 MPa), impact resistance (16.27 kJ/m²), compressive strength (111.40 MPa), microhardness (9.76 HV) due to improved fiber-matrix interaction and optimal stress distribution. Thermogravimetric analysis confirmed enhanced stability and char yield in hybrid systems compared to the UPR. Other thermal analysis and flammability tests also confirmed thermal insulation capability and thermal stability of BNF laminates. GF significantly improved the composite’s overall thermal and mechanical stability than BNF. Water absorption and soil degradation, indicating acceptable performance under moderate environmental conditions. Dielectric behavior and light absorbing ability improved opto-electronic insulation potential with increased BNF. This demonstrates that hybrid composites can serve as lightweight, cost-effective, and sustainable alternatives for structural applications in automotive, construction, and industrial sectors. • Optimal 2 wt% BNF- 6 wt% GF hybrid shows superior mechanical performance. • Thermomechanical stability enhanced by GF reinforcement. • BNF improves thermal, electrical, and optical insulation properties. • Hybrid composites maintain structure under ambient and soil exposure. • Lightweight, durable, and eco-friendly composite, ideal for structural use.