Palm-Based Polyurethane with Soybean Phosphate Ester as a Fire Retardant

Palm-based polyurethane (PU) with soybean oil phosphate ester (PE) as a fire retardant was prepared. The effect of PE to the mechanical and burning properties of the PU was investigated. The PE was synthesized via ring-opening hydrolysis between o-phosphoric acid (o-H3PO4) and epoxidized soybean oil. The synthesis was conducted at 60-70 degree Celsius. The concentration of o-H3PO4 was varied at 2.5, 5.0 and 7.5 wt %. PE with 2.5 wt % H3PO4 showed the lowest acid value (2.8 mgg-1) but high hydroxyl value (351.6 mgg-1) PU containing PE (PU-PE) has higher density (60-61 kgm-3) compared to control PU (49.7 kgm-3). Burning rate decreased from 2.16 x 10-3 ms-1 for control PU to 1.26 x 10-3 ms-1, 1.06 x 10-3 ms-1 and 0.6 x 10-3 ms-1 for PU-PE at 5, 10 and 15 wt % PE respectively. However, the addition of PE into the PU system gradually decreased the compression stress and modulus of the PU-PE. (author)