Rigid polyurethane foam-based palm oil polyol/polyepropylene glycol blend

Abstract

A mixture of palm oil polyol (POP)-polyethylene glycol (PEG) was prepared by mixing POP with either PEG600 or PEG1000 at 1.5:1 wt% ratio. The mixture was then reacted with polymeric 4, 4-diphenylmethane diisocyanate (p-MDI) to form rigid polyurethane foam (PU). Effects of POP-PEG blend on thermal stability and morphological property of PU foam were investigated. Fourier transform infrared (FTIR) analysis confirmed the formation of urethane linkages at the peaks of 1507.40 cm-1–1508.84 cm-1 in all samples. Meanwhile, the degradation temperatures of both POP-PEG foams (3320C) were higher than that of pure POP foam (2980C) at 20% wt loss, indicating an improvement of thermal stability. Scanning electron microscopy (SEM) images showed that control POP and POP-PEG1000 foams had comparable closed cell sizes and uniform cell shapes, while POP-PEG600 showed distorted cell shape which related to foam stability. To improve the POP-PEG600’s foam stability, the amounts of silicone surfactant as foam stabilizer were varied at 2%, 2.5% and 3% part per hundred polyol (pphp) in the formulation. However, it was found that by increasing the surfactant loadings did not give significant effect on thermal stabilities and foam cell morphologies. Only sample with 3.0% pphp surfactant showed bigger cell size with regular cell shape.