Development and optimization of a bio-based adhesive from euphorbia trigon latex reinforced with alumina for sustainable wood bonding applications

• Sustainable Bio-Adhesive: Developed from Euphorbia trigon latex reinforced with alumina (Al₂O₃), offering an eco-friendly alternative to synthetic adhesives. • Optimized Performance: Achieved 7.7 MPa lap shear strength and 3585 mPa·s viscosity at 40 % latex, 30 % alumina, and 30-minute mixing. • Enhanced Properties: Alumina improved mechanical strength and thermal stability (decomposition >400 °C), confirmed by FTIR analysis. • Economic & Environmental Benefits: Uses local, non-food resources, reducing import dependency and supporting sustainability. • Industrial Potential: Meets ASTM standards for wood bonding, with potential for broader applications. • Future Work: Further studies on water resistance, aging, and scalability recommended. • This research advances green adhesive technology with a high-performance, sustainable solution. The environmental and health concerns associated with petroleum-based synthetic adhesives, particularly their non-biodegradability and emission of volatile organic compounds (VOCs), have been widely recognized. As a result, increased attention has been given to the development of sustainable, bio-based alternatives. However, natural adhesives have often been limited by inadequate mechanical strength, low thermal stability, and poor durability. In this study, a bio-adhesive was formulated from Euphorbia trigon latex, an underutilized, non-edible, and drought-tolerant plant, by reinforcing it with alumina (Al₂O₃) to enhance its performance characteristics. Improvements in structural integrity and thermal resistance were targeted while maintaining environmental sustainability. A Central Composite Design (CCD) under Response Surface Methodology (RSM) was employed to optimize the formulation parameters. The effects of latex concentration, alumina loading, and mixing time were systematically analyzed. An optimized formulation comprising 40 % latex, 30 % alumina, and a mixing time of 30 min was obtained. Under these conditions, a lap shear strength of 7.7 MPa, a viscosity of 3585 mPa·s, and a thermal decomposition temperature exceeding 400 °C were achieved. These results indicate that the developed bio-adhesive can serve as a viable and eco-friendly alternative to synthetic adhesives for wood bonding, particularly in regions where cost-effective and locally sourced materials are desired.