Mathematical Modeling Techniques to Predict Important Aspects of k-Factor Aging of CFC-11 Free Rigid Insulation

Abstract

The use of ozone depleting, so-called hard CFCs as blowing agents for rigid PU foams is presently experiencing considerable political and legislative pressure, to such an extent that a complete ban of these substances is expected within the foreseeable future. Consequently, there exists an urgent need for new thermal insulation technologies based on alternative, non-ozone depleting products. Two of the options which are available for these technologies are: (a) A partial or total replacement of CFC-11 by CO 2 . Problems with this approach include severe dimensional stability problems for unfaced foams at high CO 2 levels, as well as a significant deterioration of thermal insulation capacity (k-factor)