Perfluorinated Chemistries Technologies and Alternatives Richard Holt BIAC
Perfluorinated Chemistries: Technologies and Alternatives Richard Holt BIAC 1
Limitations for any Discussion of Alternatives Numerous alternatives Time constraints Competitive considerations Anti-trust considerations Knowledge base – proprietary uses and formulations 2
Primary Current Transition Path Surfactants From >6 -Carbon to 4 -Carbon-based sulfonate chemistry From >8 -Carbon to <6 -Carbon Fluorotelomer chemistry From 8 - and 9 -Carbon Perfluorocarboxylate Polymerization Aids (PFOA/PFNA) to certain Mono- and Poly-perfluoroethers or other substances Surface Modification Polymers From >6 -Carbon to 4 -Carbon-based sulfonate chemistry From >8 -Carbon to <6 -Carbon Fluorotelomer chemistry Requires cooperation from manufacturers in a wide range of downstream industries, from consumer product manufacturers to defense and aerospace industries 3
Potential Alternatives In Kind: Fluorinated C 6: Fluorotelomer-based six fluorinated carbon functionality compounds C 4: Electrochemical fluorination-based four fluorinated carbon functionality compounds Perfluorobutane sulfonate (PFBS) Mono- and poly-fluorinated ether functionality compounds (e. g. , CF 3 or C 2 F 5 fluoroalkyl polyethers) Fluorinated oxetanes Other fluorinated polymers 4
Potential Alternatives Not-in-kind Hydrocarbons Propylated naphthalenes or biphenyls Fatty alcohol polyglycol ether sulfate Sulfosuccinate Hydrocarbon surfactants Naphthalene derivatives Siloxanes and silicone polymers 5
Do The Alternatives Work? 6
The transition from the current highly effective products to suitable alternatives has been accomplished with the following criteria as guidelines: • Efficacy of use be maintained • Reduced biopersistence • Minimization of customer disruption • Value in use be maintained • Critical societal uses are not compromised • Reduction of the environmental footprint 7
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). 8
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. 9
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 EPA More information at http: //epa. gov/oppt/pfoa/pubs/altnewchems. html * EPA presentation April 19, 2010 (Las Vegas, Nevada USA) and various other industry and trade meetings 10
Fluorinated Products - Technology Synthesis Origin Electrochemical fluorination (ECF) Fluorotelomer Fluoro(poly)ether Fluorinated oxetane Unique Properties • Lower aqueous surface tension = wetting power • the power to spread and coat surfaces • Function at very low concentrations • 100 parts per million • Work well in tandem with hydrocarbon and silicone surfactants • Unique function in “dynamic” systems 11
Electrochemical Fluorination (ECF) Products H(CH 2)n. SH aliphatic mercaptan HF, e- F(CF 2)n. SO 2 F Sulfonyl fluoride An Example of New Products based on n F(CF 2)n. SO 3 X PFDS n = 10 PFOS n = 8 PFHx. S n = 6 PFBS n = 4 F(CF 2)n. SO 2 N(R)CH 2 OH Perfluoroalkyl sulfonamido ethanol Perfluorobutane sulfonyl (PFBS) Chemistry C 4 F 9 SO 2 - R PFBS = C 4 F 9 SO 3 Potential degradation product 12
Fluorotelomer-based Products CF 2=CF 2 (TFE) F(CF 2)6 I Perfluoroalkyl Iodide F(CF 2)6 CH 2 I Fluorotelomer Iodide F(CF 2)6 CH 2 OH Fluorotelomer Alcohol An Example of New Products based on n=6 Phosphate Ethoxylate Betaine Potential degradation product PFHx. A, perfluorohexanoate: F(CF 2)5 CO 213
Pharmacokinetics in Monkey: PFBS and PFHx. A (ng/m. L) PFBS PFHx. A (hr) Serum concentration of PFHx. A or PFBS after single intravenous administration 14
Fluoropolyether (PFPE) Surfactants PFPE-diol raw material HOCH 2 -CF 2 O-(CF 2 O)m-(CF 2 O)n-CF 2 CH 2 OH MW 1500 AMU; Made by photooxidation including tetrafluoroethylene (TFE) Phosphate ammonium salt Carboxylate ammonium salt Ethoxylated diol 15
Summary for the Alternatives exist for nearly all current uses There are some uses still for which adequate replacements have not yet been identified Alternatives with a shorter fluorinated alkyl chain are still environmentally persistent but not bioaccumulative The C 4 sulfonate and the C 6 carboxylate have shown different pharmacokinetics (shorter halflife) and lower toxicity than PFOA and PFOS Non-fluorinated alternatives do not work as well 16
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! 17
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