Effect of Silicon-Based Surfactant on Compression Strength, Morphology, and Flammability of the Aluminium Hydroxide-Filled Rigid Polyurethane Foam

This study investigates the impact of Niax TM Silicone L-5440, a silicon-based surfactant, on the foaming behaviors of rigid polyurethane foam (RPUF) filled with aluminium hydroxide (ATH). The aim is to understand the effect of the surfactant on the compression strength, morphology, and flammability of the foam. Various concentrations of the surfactant, ranging from 0.5 to 3 pphp, were incorporated into the RPUF/ATH blend. Five key parameters were examined, including density, closed-cell content, structural characterization using scanning electron microscopy (SEM), compressive strength, and UL-94 rating. The results revealed that adding the silicon surfactant significantly influenced the foam properties. Foam formulations with lower surfactant concentrations resulted in denser foam with a higher percentage of closed cells (86.24%). The morphology of the foams exhibited variation in average pore sizes, initially decreasing and subsequently increasing with increasing surfactant concentration. Notably, the compressive strength of the foam increased when the surfactant concentration reached 1 pphp. Moreover, the inclusion of the surfactant improved the flammability characteristics, as evidenced by a UL-94 rating of V-1 without dripping.