Preparation of Mullite/PU Nanocomposites by Double Waste Co-Recycling

The massive accumulation of industrial waste has become an environmental problem that is very difficult to deal with. In this paper, mullite whisker nanomaterials were developed independently using industrial waste residues, which were used to degrade polyurethane (PU) solid waste by alcoholysis with ethylene glycol (EG) and ethanolamine (ETA) bi-component, and mullite modified regenerated polyol materials were obtained by double waste synergistic recycling. Mullite/PU foam nanocomposites were prepared by one-step foaming. The analysis of the test results shows that, at EG/ETA = 2:1 and mullite whisker addition of 0.15%, the regenerated rigid PU foam obtained has low thermal conductivity and higher compressive strength, at which time the regenerated PU foam has the best performance. The FTIR test results show that the silanol of mullite reacts with isocyanate during foaming and is attached to the polyurethane chain, such that the compressive strength and thermal insulation properties are maximized. It provides a new way to create a “double waste synergy” for preparing high-value materials by comprehensively utilizing resources.