INVESTIGATING THE THERMAL QUALITIES OF BIOCOMPOSITE LIGNIN FOAM PRODUCED FROM 𝘈𝘳𝘦𝘯𝘨𝘢 𝘱𝘪𝘯𝘯𝘢𝘵𝘢 (KAONG) FRUIT WASTE WITH NON-TOXIC ADDITIVES

ABSTRACT Polyurethane foams are versatile materials favored for their multiple industrial uses. However, these foams are plastic, conventionally derived from non-renewable and non-biodegradable petrochemicals. Studies have addressed this by partly or wholly replacing petrol with lignin, a renewable biopolymer. Yan et al. (2024) produced pure, rigid lignin foams from kraft lignin via cold press and baking, the results focusing on how moisture level affects morphology and porosity. However, the resultant foams faced brittleness and fragility issues. Through their methods, this study focused on biocomposite kaong-lignin foams with varying moisture levels of 1.2, 1.4, and 1.6 mL and how they influence thermal resistance, conductivity, and density, coupled with non-toxic additives to reduce rigidity. Kaong fruit shells and stalks in equal parts were ground and fractionated through choline chloride:lactic acid DES methods. After washing, a gravimetric analysis of purity revealed 55% ethanol solubility, interpreted as lignin. The entire extracted DES lignin was combined with PVA, starch, and glycerin to enhance morphology. Sample moisture levels of 0, 1.2, 1.4, and 1.6 mL per total sample volume were molded and baked at 10 degrees celsius/minute up to 240 degrees celsius and cooled to room temperature. The experimental samples were weighed and tested for thermal values through the hot plate method. Results showed that the 1.4 mL sample resulted as the foam with the highest resistance to heat, lowest conductivity, and lowest density. Additionally, it was found to be the non-significant sample compared to positive control in thermal resistance, possibly indicating comparable performance. All foams demonstrated inherent insulation properties relative to the negative control. Density analysis revealed significant differences compared to standard PUF but not relative to the 0 mL kaong foam. This research highlights the thermal capabilities of DES kaong-lignin foam formed with eco-friendly approaches and materials, combating petrol derivation without compromising intrinsic foam qualities.