Preparation and Properties of Palm Oil-Based Rigid Polyurethane Nanocomposite Foams

In this study, palm oil-based polyurethane (PU)/montmorillonite (MMT) nanocomposite foams were produced via an in situ polymerization method. The palm oil-based polyol synthesized by transesterification reaction of palm oil and pentaerythritol was reacted with commercial polymeric diphenylmethane diisocyanate in the presence of water (blowing agent), N,N-dimethylcyclohexylamine (catalyst), polydimethylsiloxane (surfactant) and MMT to produce rigid PU nanocomposite foams. The obtained foams containing different MMT contents (1, 3, and 5 wt%) were characterized for their structure, morphology, density, hardness, compressive strength and thermal stability. X-ray diffraction patterns revealed that the nanocomposites formed were exfoliated. Scanning electron micrographs showed that the cells of the obtained PU foams were closed cells. The nanocomposite foams showed a higher number of cells with a smaller cell size as the amount of MMT increased. The density and the compressive strength of the foams increased with the increasing amount of MMT and were in the range of 38.5-46.6 kg/m(3) and 116.7-171.6 kPa, respectively. Moreover, addition of MMT also improved the thermal stability of the foams.