Dispersion of polymeric-coated–silica aerogel particles in unsaturated polyester composites: effects on thermal-mechanical properties

The thermal-mechanical properties of unsaturated polyester (UP) composite were enhanced by the dispersion of silica aerogel (SA) with preserved pores. Low-cost SA was prepared from rice husk via the sol-gel process and ambient pressure drying. A new method was proposed to encapsulate the hydrophobic aerogel surface pores with hydrophilic polyvinyl alcohol (PVA) film using the fluidized-bed coating process. The dispersion of PVA-coated aerogel with preserved pores in the polyester matrix resulted in an increase of specific compressive strength (44.1 MPa · cm3 g−1), thermal insulation (0.23 W m−1 K−1), and thermal stability (Tonset = 310°C), but decreased the glass transition temperature (Tg = 260°C)