Facile preparation of mechanically strong polyvinyl alcohol/MTMS aerogel composites with improved thermal stability

To overcome the poor mechanical performance of methyltrimethoxysilane (MTMS) aerogels and the low thermal stability of polyvinyl alcohol (PVA), the PVA/MTMS aerogel composites (PMAC) were successfully prepared through a facile impregnation process. It finds that the PVA concentration has a great influence on the physicochemical properties of the PMAC, which has been investigated in detail. It further turns out that the density (0.081 ~ 0.152 g/cm3) increases linearly along with the PVA concentration, while the thermal conductivity (32.9 ~ 51.7 mW/m/K) increases monotonously first and then keeps almost unchanged. The hydrophilicity of PMAC can be tailored by adjusting the PVA concentration. Compared with the pure MTMS aerogel and PVA, the thermal analysis reveals that the PMAC shows an improved thermal stability. Although the physical combination is verified between the MTMS aerogel and PVA, the mechanical performance of the PMAC is still significantly enhanced with the Young’s modulus and compressive strength reaching up to 20.35 MPa and 970.33 kPa, respectively. All these results suggest that the introduction of PVA into MTMS aerogel is feasible and effective for acquiring better performance for the aerogel composites, which contributes to extending their potential applications.