The utilization of egid polyurethane-polyisocyanurate foams by the combined alcoholysis-aminolysis process
Polimery 2002, No 2, 104
Rigid PUR—PIR foams prepared (i) with addition or (ii) with no addition of a solid fraction of rye slops or potato slops were both alcoholyzed and aminolyzed. The alcoholyzate was used to replace the original polyether polyol, 0.05—0.20 of chemical equivalent, which is used to prepare foams (Table 2). Three senes of foams were prepared,vyarying in the amount of the alcoholyzate added. Apparent density, compression strength, brittleness, oxygen index, combustion residue, stability of linear dimensions, volume change (in 48 h at 120 °C), and softening point (Table 3, Figs. 2—4) were determined. As the proportion of the alcoholyzate was raised from 0.05 to 0.2 chemical equivalent, the compression strength of the mode (ii) foams (foams 1.1—1.4) rose, whereas brittieness, oxygen index and softening point remained practically unaffected as compared with control foam (foam 1.0 with no alcoholyzate added). In the mode (i) foams (solid fraction of rye slops added) prepared with the alcoholyzate added (foams 2.1—2.4), the compression strength rose but slightly (from 208.7 kPa in control foam to 229.0 kPa in foam containing 0.2 chem. equiv. of alcoholyzate) and the brittleness and softening point fell. The foams containing the alcoholyzate and the solid fraction of potato slops (foams 3.1—3.4) exhibited not only lower brittleness and reduced softening points but also lower compression strengths. In each foam examined, the oxygen index and combustion residue remained practically unaffected as compared with controls. IR spectra confirmed the presence of the urethane and isocyanurate groups in the foams prepared.
Keywords: rigid polyurethane—polyisocyanurate foams, recycling, alcoholysis and aminolysis, utilization of rye slops and potato slops, physical and mechanical properties of foams