Optimization of Formulations Based on HFC-365mfc and Blends Thereof

Abstract

As already mentioned in our last SPI publications, HFC-365mfc has to be considered as a key building block for a new generation of blowing agents. Interesting blends have been identified in order to answer the demand of the various segments of the rigid foam market. New PU formulations based on HFC-365mfc and blends have now been developed for the laboratory scale.

Whilst the use of HCFC-141b was found to be easy thanks to its good solubility characteristics in standard polyols, the use of HFCs, notably HFC-365mfc is more difficult. Indeed, because of their low polarity, the solubility of HFCs in most standard polyols is limited. This is advantageous for dimensional stability but means that the systems that are being used now will need to be adapted in order to obtain a homogeneous polyol blend.

In this paper, we report on ways to increase the compatibility of HFC-365mfc and blends thereof with polyol systems. The evaluation of foams obtained from these new systems has also been performed in order to allow the selection of the most appropriate combination for a given application.

Foaming trials using the non flammable blend HFC-365mfc/HFC-134a will be presented, especially for spray foam, and one trial using the azeotrope HFC-365mfc/n-pentane for PIR laminates. The main properties being reported are notably the resulting pressure above system premixes, the dimensional stability and the foam thermal conductivity.

SOLVAY have taken the decision to start a pilot plant for HFC-365 mfc in September 1999, and commercial production is planned to come on stream in the year 2002.