Physical, Mechanical, and Microstructural Characterization of Guinea Corn Husk Particleboards Bonded with Gum Arabic and Recycled PET

Abstract

Traditional wood-based particleboards (PBs) heavily rely on amino-formaldehyde synthetic resins, a paradigm that exacerbates global deforestation and presents severe carcinogenic health hazards via volatile emissions. To address these ecological and toxicological vulnerabilities, this study investigates a novel, eco-friendly composite architecture utilizing guinea corn husk (GCH) as a bio-based filler matrix, integrated with a hybrid binder system composed of polyethylene terephthalate (PET) and gum Arabic (GA). A systematic formulation strategy was deployed, maintaining a constant 70 wt.% GCH loading while systematically varying the PET-to-GA binder ratios across six discrete configurations: 0/30, 5/25, 10/20, 15/15, 20/10, and 25/5 wt.%. The resulting composites underwent comprehensive macro-characterization to quantify their physical and mechanical phenotypes, specifically analyzing bulk density, fluid transport kinetics (water absorption and thickness swelling), alongside quasi-static mechanical profiles (compressive strength, axial and split tensile strengths, flexural response, and modulus of elasticity). To elucidate the underlying structural mechanics, microstructural evolution and elemental distributions were mapped via scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The hybrid panels demonstrated excellent hydro-resistance, restricting water absorption to 3.15–9.81% and thickness swelling to 3.58–9.02%. The empirical data reveals that escalating PET fractions dramatically optimize both the dimensional stability and the load-bearing capacity of the network through improved interfacial binding. Ultimately, these green composites successfully satisfy institutional threshold standards for non-load-bearing engineering applications, establishing a compelling, high-performance, and low-emission vanguard to displace legacy wood-formaldehyde panels.