Hybrid Organic–Inorganic Composites Based on Glycolyzed Polyurethane

Abstract

We present a simple approach to upcycle glycolyzed polyurethane foam products by fabricating robust, highly filled organic/inorganic composites (46–60 wt % solid loading). These composites, consisting of recycled polyols, naturally occurring or synthetic aluminosilicate minerals, and isocyanate linkers, are shown to possess superior mechanical (flexural) properties compared to ordinary Portland cement (OPC). Optimization of chemical composition (isocyanate and inorganic content) and curing temperatures (25–50 °C) results in low-density composites (up to 3× less dense than OPC) with flexural strengths comparable to OPC while exhibiting strain capacities up to 5× as compared to OPC-based systems. In contrast, parallel fabrication approaches using low OH-value virgin polyols resulted in flexible composites and much lower flexural strengths, highlighting the advantage of employing high −OH density recycled polyols. Variations in the flexural strength of the composites were correlated with differences in their morphology─uniformity in the distribution of inorganic particles contributed to improved flexural properties. The generality of this fabrication approach is demonstrated using quartz sand as the inorganic particle and recycled polyols with different hydroxyl values.