Evaluation of the next generation HFC blowing agents in rigid polyurethane foams

The development of a third generation HFC blowing agent has achieved significant progress in the past few years. Several candidates have been identified as promising substitutes for HCFC-141b in foam applications. Elf Atochem has striven to provide alternatives after HCFC-141b phases out in foam applications. This paper summarizes our recent research activities in HFCs in rigid polyurethane foam applications. It includes determinations of the weight loss of blowing agents during the foaming process. To predict long term aging behavior of polyurethane foams, we measured effective diffusion coefficients of HFC-245fa, HFC-365mfc and HCFC-141b. Also, stability of the foam systems (PUR and PIR) using HFC-365mfc as the blowing agent will be reported. The stability is indicated by the amount of decomposition during a certain period of time. Furthermore, we have studied effects of HFC-245fa foam density on the foam insulation (k-factor), dimensional stability and compressive strength. In this study, we also determined aged k-factors of HFC-245fa and HCFC-141b foams with different foam densities. Finally, we investigated HFC-134a in PUR foam as well as its solubility in several polyols.