Benefits: Effective, environmentally acceptable foam insulation materials that are non-ozone depleting and do not appreciably contribute to global warming.

Approach: Both polyisocyanurate board insulation and polyurethane refrigerator insulation are now blown primarily with HCFC-141b. By the Montreal Protocol, production of this chemical for use as a blowing agent must cease by 2003, and a new, non-ozone-depleting chemical is needed as a replacement. Thermal performance data and aging characteristics for foams blown with various alternative blowing agents are needed to allow the best choice of a new blowing agent to be made. Future blowing agents will probably be needed that have both zero ozone-depletion and global warming potentials.

A study is under way on the aging characteristics of simulated refrigerator panels containing polyurethane (PUR) foam blown with third-generation blowing agents sandwiched between semi-permeable plastic liners. Thermal tests have been completed on these panels after two years of aging at controlled temperatures, and continued testing is planned at six-month to one-year intervals. As part of this study, accelerated aging tests have been performed on thin slices of core foam material from these panels, and these specimens will continue to be monitored. Long-term aging experiments will be conducted with simulated refrigerator panels blown with second-generation blowing agents that were started as part of a cooperative project with the Appliance Research Consortium (ARC) CRADA.

In addition, the project will continue to develop models to predict the aging characteristics of composite panels containing foam and facers and will develop auxiliary data (e.g., gas diffusion coefficients) that are needed by the models. The quality of the facer/foam bond has been identified as one of the critical performance metrics that presently is not well understood. Laboratory tests to quantify this parameter are not available. A new effort will be initiated this year to study the issue and to assist industry in developing a test method to quantify this parameter.