Preparation and characterization of flame retardant bio-based polyols polyurethane foam

In this paper, two different soybean oil-based polyols (Polyol-E and Polyol-PPOA) were prepared by ring-opening reaction of epoxidized soybean oil with ethanol and phenylphosphoric acid, respectively. Rigid polyurethane foams of all bio-based polyols were prepared by combining them with isocyanate (PM200) according to different ratios. The cell structure, density, mechanical properties, and flame retardant properties of the prepared rigid polyurethane foams were tested and analyzed. The results of scanning electron microscopy showed that with the increase of the mass fraction of Polyol-PPOA, the number of cells in the samples first decreased and then increased, and when the content of Polyol-PPOA increased, the cell size first increased and then decreased. The density increased first and then decreased with the amount of Polyol-PPOA. The compressive strength showed a trend of first decreasing and then increasing. When the Polyol-PPOA was 70% (mass), the compressive strength reached 0.133 MPa, and the residual carbon rate reached 17.57% at 800℃. The limiting oxygen index also reached the highest at this time, which was 23.10%. Through experiments, it can be found that the rigid polyurethane foam material prepared by using mixed polyols can not only have a certain mechanical strength but also improve a certain flame retardant performance. © 2023 Chemical Industry Press. All rights reserved.