Thermal insulation of silica aerogel/PMMA composites with amino-capped polydivinylsiloxane phase interfaces

Contradictions of strength and thermal insulation of silica aerogel (SA) are of wide concern. In this research, the mesoporous structure of SA was grafted with the polymers to increase the strength of SA and decrease the thermal conductivity of composites. The composites were characterized and analyzed using field emission scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, the thermal gravimetric analyzer (TGA), multi-assay gel permeation chromatography (GPC), a microcomputer control electronic universal testing machine and so on. The results indicated that amino-capped polydivinylsiloxane (AP) was successfully grafted on the SA surface and polymerized with methyl methacrylate (MMA) to form an AP high thermal insulation phase interface between the SA phase and poly(methyl methacrylate) (PMMA) phase. The SA-AP/PMMA composite with a covalent bonding high thermal insulation phase interface had better mechanical properties and compressive strength than those of SA/PMMA. The obtained composite was an excellent thermal insulation material with lower thermal conductivity [0.045 W/(m . K)].