Presentation on theme: "Perfluorinated Chemistries:"— Presentation transcript:
1 Perfluorinated Chemistries: Technologies and AlternativesRichard HoltBIAC
2 Limitations for any Discussion of Alternatives Numerous alternativesTime constraintsCompetitive considerationsAnti-trust considerationsKnowledge base – proprietary uses and formulations
3 Primary Current Transition Path SurfactantsFrom >6-Carbon to 4-Carbon-based sulfonate chemistryFrom >8-Carbon to <6-Carbon Fluorotelomer chemistryFrom 8- and 9-Carbon Perfluorocarboxylate Polymerization Aids (PFOA/PFNA) to certain Mono- and Poly-perfluoroethers or other substancesSurface Modification PolymersRequires cooperation from manufacturers in a wide range of downstream industries, from consumer product manufacturers to defense and aerospace industries
4 Potential Alternatives In Kind: FluorinatedC6: Fluorotelomer-based six fluorinated carbon functionality compoundsC4: Electrochemical fluorination-based four fluorinated carbon functionality compounds - Perfluorobutane sulfonate (PFBS)Mono- and poly-fluorinated ether functionality compounds (e.g., CF3 or C2F5 fluoroalkyl polyethers)Fluorinated oxetanesOther fluorinated polymers
5 Potential Alternatives Not-in-kindHydrocarbonsPropylated naphthalenes or biphenylsFatty alcohol polyglycol ether sulfateSulfosuccinateHydrocarbon surfactantsNaphthalene derivativesSiloxanes and silicone polymers
7 The transition from the current highly effective products to suitable alternatives has been accomplished with the following criteria as guidelines:Efficacy of use be maintainedReduced biopersistenceMinimization of customer disruptionValue in use be maintainedCritical societal uses are not compromisedReduction of the environmental footprint
8 Non-Fluorinated Alternatives Non-fluorinated alternatives, such as different hydrocarbon surfactants and silicone products, have been identified… however, in most cases or at least in larger application areas, other fluorinated compounds are used instead…. non-fluorinated alternatives do not work as well, especially in situations, where extreme low surface tension is needed (Danish EPA, 2006).
9 Effectiveness of Newer Alternatives: What are we finding? C-6 and C-4 chemistries adequately meet the criteria for replacement of most current C-8 and higher homologue uses.
10 New Chemical Review of Alternatives* US EPA is reviewing substitutes for Long Chain PFCs as part of its review process for new chemicals under EPA's New Chemical Program– Ongoing since 2000– Consistent with the approaches to alternatives encouraged under the PFOA Stewardship Program– Over 100 alternatives of various types have been received and reviewed by EPAMore information at* EPA presentation April 19, 2010 (Las Vegas, Nevada USA) and various other industry and trade meetings
11 Fluorinated Products - Technology Synthesis OriginElectrochemical fluorination (ECF)FluorotelomerFluoro(poly)etherFluorinated oxetaneUnique PropertiesLower aqueous surface tension = wetting powerthe power to spread and coat surfacesFunction at very low concentrations100 parts per millionWork well in tandem with hydrocarbon and silicone surfactantsUnique function in “dynamic” systems
12 Electrochemical Fluorination (ECF) Products H(CH2)nSH aliphatic mercaptanAn Example of New Products based on n=4Perfluorobutane sulfonyl (PFBS)ChemistryC4F9SO2 - RHF, e-F(CF2)nSO2FF(CF2)nSO3XSulfonyl fluoridePFDS n = 10PFOS n = 8PFHxS n = 6PFBS n = 4F(CF2)nSO2N(R)CH2CH2OHPerfluoroalkyl sulfonamido ethanolPFBS = C4F9SO3-Potential degradation product
13 An Example of New Products based on n = 6 Fluorotelomer-based ProductsCF2=CF (TFE)F(CF2)6IPerfluoroalkyl IodideAn Example of New Products based on n = 6PhosphateEthoxylateBetaineF(CF2)6CH2CH2IFluorotelomer IodideF(CF2)6CH2CH2OHFluorotelomer AlcoholPotential degradation productPFHxA, perfluorohexanoate: F(CF2)5CO2-
14 Pharmacokinetics in Monkey: PFBS and PFHxA (hr)(ng/mL)PFBSPFHxASerum concentration of PFHxA or PFBS aftersingle intravenous administration
15 Fluoropolyether (PFPE) Surfactants PFPE-diol raw materialMW 1500 AMU; Made by photooxidation including tetrafluoroethylene (TFE)Phosphate ammonium saltCarboxylate ammonium saltEthoxylated diolHOCH2-CF2O-(CF2O)m-(CF2CF2O)n-CF2CH2OH
16 Summary for the Alternatives Alternatives exist for nearly all current usesThere are some uses still for which adequate replacements have not yet been identifiedAlternatives with a shorter fluorinated alkyl chain are still environmentally persistent but not bioaccumulativeThe C4 sulfonate and the C6 carboxylate have shown different pharmacokinetics (shorter half-life) and lower toxicity than PFOA and PFOSNon-fluorinated alternatives do not work as well
17 Summary for the Alternatives PFOS and PFOA are some of the most studied chemicals, therefore ...Alternatives will almost always have less supporting data, however ...Adequate supporting data have been submitted to obtain regulatory approval, generally subject to requirements to submit additional data to robustly define hazard and exposure profiles.Good business move for the future!
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