Synthesis and properties of melamine–starch hybrid aerogels cross-linked with formaldehyde

Abstract

We reported the synthesis of melamine–starch–formaldehyde aerogels by using starch and melamine cross-linked with formaldehyde. The gelation time of melamine–starch–formaldehyde gels prepared at different concentrations and ratios of reactants, pH and heating temperature were studied and discussed. The results indicated that the gelation time reduced with the increase of reactant concentrations and heating temperature, and decrease of starch/melamine–formaldehyde mass ratio and pH. The structural properties of melamine–starch–formaldehyde aerogels were also characterized by the field emission scanning electron microscopy, the Brunauer-Emmett-Teller methods, the X-ray diffraction, the fourier transform infrared spectroscopy, and the dynamic mechanical analyzer. It was found that all the melamine–starch–formaldehyde aerogels showed a typical three-dimensional porous structure and their surface areas decreased with increase of the density. Furthermore, the compressive stress as a function of strain was measured to study the mechanical properties of the melamine–starch–formaldehyde aerogels. Because of potentially lower cost, the high surface areas, relatively large pore volume, low-bulk densities and excellent mechanical performance, the melamine–starch–formaldehyde aerogels would have potential for use in construction and building materials.

Graphic Abstract

MSF aerogels were successfully prepared. The starch/MF mass ratio played an important role in the gelation and structural properties. The gelation process became faster with the increase of starch/MF mass ratios. The MSF-1 aerogel has a large surface area (384.6 m²/g), highly ordered mesopores with uniform pore size (17.9 nm) and pore volume (1.63 cm³/g). To study the mechanical properties of the hybrid aerogel, it was found that the MSF-1 aerogel possessed excellent elasticity and mechanical durability.