Rigid polyurethane foam based on modified soybean oil

Two bio-based polyols (Polyol-r and Polyol-t) were synthesized from commercially available epoxidized soybean oil (ESBO). Polyol-r was obtained from ring opening of ESBO in the presence of fluoboric acid, while Polyol-t from a transesterification of Polyol-r with glycerol through a litharge catalyst. A rigid polyurethane foam was prepared by mixed polyols (Polyol-t and commercial 635 polyether polyol) with 4,4'-methylene-bis(phenyl isocyanate). The hydroxyl value of Polyol-t was higher than that of Polyol-r, which was also backed up by Fourier transform infrared spectrometry. Scanning electron microscope examination revealed that the foam has closed cells. The test of performances of the foam shows that it possesses an excellent dimension stability and compressive strength.