Structural, mechanical, thermal, and thermomechanical properties of phenolic silica nanocomposites.

摘要

In order to evaluate the structural, mechanical, thermal, and thermomechanical properties of phenolic silica nanocomposites, we developed phenolic silica nanocomposites using two different techniques. In the first case, nano silica particles were dispersed within phenolic matrix, whereas in the second case, the nano silica particles were condensed in situ with the matrix by using sol-gel technique.; Our thermal analysis of the curing reaction of the phenolic resin, when its physical dimensions are in nano scale, indicated that the curing reaction temperature and enthalpy were dependent on the physical size of the material. Furthermore, the formation of Si-O-Si bonds during the condensation of the silicon hydroxides within a phenolic matrix perturbed the curing reaction of the resin.; X-ray diffraction measurements of both the nanocomposites irrespective of their mode of fabrication showed only a broad peak at 2theta = 18.6° due to the diffraction by the adjacent polymer chains. Our scanning electron microscope images, on the other hand, indicated that the silica particles in both cases were actually formed from the networking of smaller silica particles.