Preparation of Thermally-Insulating Polyurethane Foams with Modified Silica Aerogel

초록

Polyurethane foams are prepared based on polyol and isocyanate for the applications as thermal insulator with low thermal conductivity. To improve the thermal insulating capability of polyurethane foams, modified silica aerogels were added as solid additives. We added them during the foaming process to reduce pore size and increase porosity in polyurethane foam. Silica aerogels were modified with perfluoroalkylsilanes. In the foaming process, additives were dispersed in isocyanate with higher dispersibility, and mixed with polyols under continuous stirring. Adding perfluoroalkylsilanes with low surface tension as a solid additive, the activation energies required for nucleation were reduced to form smaller and dense foams. The morphology, surface topology and thermal conductivity of polyurethane foams were investigated by SEM, TEM, thermal conductivity analyzer.