POLYURETHANE-BASED AEROGELS FOR USE AS ENVIRONMENTALLY ACCEPTABLE SUPER INSULANTS

The introduction of ''VACPAC'' panels (polyurethane-based vacuum insul ation panels) into the appliance market have been discussed extensivel y. Extensive field tests have been carried out and, recently, several commercial models have been launched based on ''VACPAC'' panel technol ogy. Researchers all over the world are now working on next generation super-insulation materials called aerogels. Aerogels are light weight , air-filled materials with a low thermal conductivity. The microporos ity of these materials greatly reduces the air conductivity. Most of t hese materials are silica based and rather brittle in nature. Some wor k has been reported on organic polymeric aerogels. Laboratory developm ent work of polyurethane- and polyisocyanurate-based organic aerogels has now been completed. These materials offer a thermal conductivity o f 7 mW/mK at a modest vacuum of 10 mbar. When no vacuum is applied, an d the aerogel is completely filled with air, the thermal conductivity is 22 mW/mK. This paper describes the factors that have been optimised to develop an aerogel material which, in the long term, it is believe d, will be a viable filler material in moderate vacuum technology. The project has been focused towards the appliance industry where energy requirements are becoming more and more stringent. Following on from t he initial laboratory development, ICI Polyurethanes is investigating the potential routes to market for such a product whilst simultaneousl y working on methods for scaling up its technology. Initial tests are in progress and further process and product optimisation is being achi eved.