Degradability of an Acrylate-Linked, Fluorotelomer Polymer in Soil

Abstract

Fluorotelomer polymers are used in a broad array of products in modern societies worldwide and, if they degrade at significant rates, potentially are a significant source of perfluorooctanoic acid (PFOA) and related compounds to the environment To evaluate this possibility, we incubated an acrylate-linked fluorotelomer polymer in soil microcosms and monitored the microcosms for possible fluorotelomer (FT) and perfluorinated-compound (PFC) degradation products using GC/MS and LC/MS/MS. This polymer scavenged FTs and PFCs aggressively necessitating development of a multistep extraction using two solvents. Aged microcosms accumulated more FTs and PFCs than were present in the fresh polymer indicating polymer degradation with a half-life of about 870-1400 years for our coarse-grained test polymer. Modeling indicates that more-finely grained polymers in soils might have half-lives of about 10-17 years assuming degradation is surface-mediated. In our polymer-soil microcosms, PFOA evidently was lost with a half-life as short as 130 days, possibly by polymer-catalyzed degradation. These results suggest that fluoratelomer-polymer degradation is a significant source of PFOA and other fluorinated compounds to the environment.

National Screening Study on 10 Perfluorinated Compounds in Raw and Treated Tap Water in France

“…These ''new'' compounds are presented as environmentally friendly alternatives, but they are difficult to remove from drinking water by common treatment techniques and are thought to become the main emerging contributors to total PFC levels in drinking water in the future (Wilhelm et al 2010). Due to their estimated half-life (Washington et al 2009), PFC precursors may constitute an important source of shorter-chained PFCs in the environment for the coming decades.…”

“…In the environment, some PFCs can degrade through biological or nonbiological processes into perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates (PFASs), which are the two most widely known groups of PFCs, and final degradation products of a variety of PFC precursors, including fluorotelomer alcohols (FTOHs), fluorotelomer sulfonates, perfluorooctane sulfonamidoethanols, and perfluorooctane sulfonamide (Lee et al 2010;Rhoads et al 2008;Washington et al 2009). PFCAs and PFASs do not break down in the environment and thus persist indefinitely.…”

“…Environmental presence of PFASs and PFCAs results mainly from two pathways: direct release from their salts, which are used as processing aids in fluoropolymer manufacturing (Prevedouros et al 2006), and indirect release through the degradation of fluorotelomer-based polymers or unbound residual precursors, whose the significant presence has been reported in a suite of consumer and industrial products (Dinglasan-Panlilio and Mabury 2006; Washington et al 2009). …”

Behavior and Fate of PFOA and PFOS in Sandy Aquifer Sediment

“…Samples were collected at a depth of 23 m below the ground surface as described by Washington et al (2009). See the Supporting Information for further details of the analysis.…”

“…In a study of the degradation of an acrylate-linked fluorotelomer polymer in soil, Washington et al (2009) observed a loss of recoverable PFOA over time and tentatively identified 2-HPFOA; CF 3 (CF 2 ) 5 CFHCOOH as a possible degradation product of PFOA. The possibility that 2-HPFOA formed in the microcosms in this study was evaluated by extracting microcosms after 740 d of incubation and analyzing these extracts for 2-HPFOA.…”