Guilin, China – The potential of polyether polyol regenerated from waste PU foam to make new insulation materials is being investigated by scientists at Guilin University of Aerospace Technology. They’re looking at its potential in aerogel-modified nanocomposites.
After cleaning and drying, the waste foam was crushed and mixed with ethylene glycol and ethanolamine, plus potassium hydroxide as a catalyst. After heating to 180°C, polyether polyol was isolated from the degradation product.
The silica aerogel was prepared at room temperature and pressure, and a small amount added to the regenerated polyether polyol, with IPDI as the isocyanate and then cyclopentane as the blowing agent. The result was a nanocomposite silica aerogel modified PU foam, with some of the aerogel reacting with the isocyanate to form carbamate linkages as part of the foam structure, and that which did not react providing physical reinforcement.
The regenerated rigid foam with an addition rate of 0.3% had low density and thermal conductivity but greater compressive strength. The good thermal insulation and strength support properties, they said, indicated that the method has potential as a new high-value use for waste PU foam, with better performance than traditional PU foam.
The work has been published in the journal Nanomaterials.