Keywords: aerogel-graphite, spray-foam, composite, building materials
Summary:Studies on insulating materials with extremely low thermal conductivity are increasingly being performed to respond to the global demand for greater energy savings. With this ongoing effort, aerogels and aerogel-enhanced materials have attracted growing attention. Aerogel is a super-insulating material with an extremely low thermal conductivity (99%), and extremely low density. In this study, a new closed-cell spray polyurethane (PU) foam with aerogel was developed and investigated. In particular, a PU foam with aerogel and graphite (PUAG) was prepared by mixing aerogel for reducing the thermal conductivity of the foam and a small concentration of graphite for improving its flame-retardancy performance. The performance of the prepared PUAG was analyzed via several tests, including density measurements, thermal-conductivity measurements, morphology examination, flame-retardancy evaluation, thermogravimetric analysis, and dynamic heat transfer analysis. A 20% reduction in the thermal conductivity compared with traditional PU was observed. Additionally, the PUAG exhibited a significant reduction in the smoke production rate and a 10% reduction in the surface peak temperature.