Properties tailoring of plant-based fiber foams via AKD-coated hollow glass microspheres: Enhanced hydrophobicity, mechanical performance, and thermal insulation

Developing eco-friendly, multifunctional plant-based foams is essential for environmental protection and energy conservation. The environmental pollution and health hazards associated with petroleum-based foam plastics are becoming increasingly evident. Using sugarcane bagasse fibers and bamboo fibers as raw materials, plant‑based fiber foams were fabricated by incorporating AKD‑coated hollow glass microspheres (HGMs) into fiber suspension, followed by foaming and drying processes. Modified microspheres were incorporated to fabricate plant-based fiber foam materials with excellent flame-retardant, hydrophobic and mechanical properties. When the hollow glass microsphere (HGM) content was 10 g and the dosage of 15 ± 0.5% solid-content alkyl ketene dimer (AKD) emulsion for HGM coating was 20 mL, the prepared foam material exhibited superior flame retardancy, hydrophobicity and mechanical strength. Its Young’s modulus reached 292.46 kPa, compressive strength was 272.36 kPa, and water contact angle (WCA) was 139.4°. Furthermore, the peak heat release rate (P-HRR) and total heat release (THR) of the foam material decreased by 32.19% and 39.52%, respectively. In addition, the limiting oxygen index (LOI) of the material increased from 18.8% to 25.6%, demonstrating an increase in the minimum oxygen concentration required for its sustained combustion. Meanwhile, the thermal stability and thermal insulation performance of the material were also enhanced. Owing to its outstanding flame retardancy, hydrophobicity and mechanical strength, this fiber-based foam material holds great promise for packaging and transportation applications of heavy flammable and explosive goods.