Hydrophobic silica aerogel glass-fibre composite with higher strength and thermal insulation based on methyltrimethoxysilane (MTMS) precursor

This research relates to the synthesis of hydrophobic silica aerogel and glass-fibre based composite with higher surface area, hence higher thermal insulating properties with strength and rigidity against mechanical damaging forces. Glass fibre mats were impregnated with different sols and subjected to freeze drying after aging at ambient temperature and pressure. The freeze drying retained the silica structure intact but removed the water from internal chaotic capillary channels. The bimodal meso and macro porous composite board was obtained. The thermal conductivity measured to be in the range from 0.021 to 0.026 W/mK with different compositions of silica sols ranging from 4% to 32%. The most important property obtained was the higher strength of the board with the 32% silica sol obtained up to 7 MPa in flexural and 4 MPa in tensile modes. Low densities and higher porosities were obtained.