HFC-365mfc: A Versatile Blowing Agent for Rigid Polyurethane Foams

Abstract

HFC-365mfc and HFC-245fa are now well documented as promising blowing agents, and their production will come on stream in a few years. However, none has the same ideal boiling point as CFC-11 or HCFC-141b. Blends may offer the best compromise to customize the different end-use requirements. Two different directions for further developments have emerged from our work: Two binary, non-azeotropic blends of HFC-365mfc with HFC-245fa or HFC-134a open the door to non-flammable blowing agents with a convenient boiling point in the range of 20 to 25°C (depending on actual composition) and a very good gas phase thermal conductivity. These new blowing agents could be safely used in the same manner as CFC-11 or HCFC-141b, but would be the most expensive option in the series of blowing agents currently under examination. It would fit the needs of foamers looking especially for non flammability (ease of handling, low investments) and optimized foam thermal conductivity. Three low boiling, binary azeotropes have been found with HFC-365mfc and the three pentane isomers (n-, iso-, and cyclo-pentane). Although these azeotropes are flammable, they open the door to more cost effective formulations with improved properties over formulations blown with straight pentane. It is anticipated that each mixed blowing agent now under investigation will find applications in specific end-uses. HFC-365mfc appears to be a key building block to design a full range of blowing agents which offers a wide flexibility to system houses and polyurethane foamers, both in the direction of non flammable or flammable blowing agents. Semi industrial trials with the blends and industrial trials with straight HFC-365mfc are reported as a practice related example of the suitability of these blowing agents.

Transport of 1,1,1,3,3-Pentafluorobutane (HFC-365mfc) in Rigid Polyurethane Foam and Polyethylene

“…The thermal conductivity of HFC-365mfc gas is 10.6mW•m -1 •K -1 at 25°C (2) . For cyclopentane many different values are given in the literature.…”

“…In the present study, the effective diffusion coefficient of HFC-365mfc in a PUR foam was found to be 1.0•10 -13 m 2 •s -1 . In the literature the values 3.1•10 -13 and 0.5•10 -13 m 2 •s -1 are given (13,1) . In an earlier study we have determined D eff to be 0.6•10 -13 m 2 •s -1 for cyclopentane (11) .…”

Cryogenic thermal insulating and mechanical properties of rigid polyurethane foams blown with hydrofluoroolefin: Effect of perfluoroalkane

“…This result is likely due to the lower surface tension of the mixed polyol solution with a PFA content of 1.0 php, which allowed the mixed polyol solution to be more uniform and led to a higher nucleation rate. 1,17 The low surface tension of PFA itself (13.9 mN/m) may contribute to the decrease in surface tension of mixed polyol solutions with PFA contents. For the PFA content of 2.0 php, however, the cell size increased up to 181 μm.…”

“…Hydrofluorocarbon (HFC), a third-generation blowing agent, has also been used to prepare rigid PU foams. 1,7,16,17 Although PU foams prepared with HFC have the advantage of low ozone depletion potential (ODP), they are also known to have high global warming potential (GWP). As a result, a formulation with a new blowing agent for the preparation of rigid PU foam is needed, as the use of HFC is restricted by various environmental regulations, including the Montreal Protocol of 2016.…”

Analysis of the Evolution of PIR Foams in the Context of the Phase Out of HCFCs

“…SOLVAY is committed to supplying a liquid zero ODP blowing agents for plastic foams as substitutes for the currently used HCFC-141b. Since 1995 we have published a series of papers on the development of HFC-365mfc as a substitute for HCFC-141b (1)(2)(3)(4)(5)(6)(7). HFC-365mfc has a boiling point of 40 C and a vapor thermal conductivity of 10.6 mW/m K, as shown in Table 1.…”