Physicochemical properties and structure of aerogel type composites on the basis of polyvinyl alcohol/carbon black

Resumo

The porous structure and physicochemical properties of aerogel type composites on the basis of polyvinyl alcohol/carbon black obtained by gas cryotreatment of a foamed composite are studied. The materials consist of more than 50 wt % carbon and have a real density of no less than 0.79 g/cm³ (the bulk density is less than 0.27 g/cm³). It is found that the molecular weight of polyvinyl alcohol and the presence of sodium tetraborate affect the size of the macropores of aerogel type composites, while carbon black does not affect this parameter. The dependence of the specific surface area of carbon black and average size of the macropores of aerogel type composites on their specific surface area is found. The thermal stability of the materials does not depend on their composition and synthesis conditions and falls within the range of 260–280°C. The thermal conductivity of the aerogel type composites on the basis of polyvinyl alcohol/carbon black is in the range of 33–59 mW/(m K). These materials are recommended for application as heat insulators.