Simple and effective route to tailor the thermal, acoustic and hygrothermal properties of cork-containing waste derived inorganic polymer composites

Abstract

Future generation building materials produced using sustainable precursors and exhibiting multifunctional properties are in huge demand, as they might be a key tool to tackle the carbon dioxide emissions from the building sector. This study provides new insights regarding the impact of the cork particle size on the hardened-state properties of inorganic polymer composites derived from fly ash waste. The composites were characterised regarding their mechanical, thermal, acoustic and hygrothermal properties. The use of smaller sized particles favours the specimens' sound insulation and moisture regulation capacity, while larger granules enhance the specimens’ mechanical performance. The best performing composite containing 80 vol% of small size cork granules shows an excellent moisture buffer value (2.22 g/m2 Δ%RH), low thermal conductivity (79 mW/m K) coupled with high sound insulation ability. In addition, the cork-composites show sound absorption frequency selectivity according to the thickness of the samples or the size of the cork granules used in their production, and this allows tuning the specimens according to the frequency of the sound pollution source. This study reduces the knowledge gap regarding the production cork-containing inorganic polymers which might foster the technology deployment.