Fluorotelomer-Based Acrylate Polymers as an Indirect Source of Perfluoroalkyl Carboxylates.

摘要

Fluorotelomer-based acrylate polymers (FTACPs) are a class of side-chain fluorinated polymers that have been widely used as surface protectants in textile, upholstery and paper industries. Despite FTACPs constituting the largest fraction of commercial fluorotelomer products, little is known about their environmental fate. This dissertation investigates the development and application of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry to directly analyze the environmental fate of model FTACPs, which was hypothesized to be a significant indirect source of perfluoroalkyl carboxylates (PFCAs).;MALDI-TOF methods were developed using a homologous series of FTACPs with fluorotelomer and hydrocarbon acrylates. The relative degree of FTACPs fluorination was demonstrated to influence the sample preparation protocol for MALDI-TOF analysis. Application of the MALDI-TOF method was used to directly determine the biodegradation of the model FTACP, poly(8:2 FTAC). Alterations to the characteristic repeat pattern of poly(8:2 FTAC) suggested biodegradation, which was consistent with the indirect analysis of PFCAs by liquid chromatography tandem mass spectrometry (LC-MS/MS). The biodegradation half-life of poly(8:2 FTAC) ranged from 8 to 111 years. Further MALDI-TOF method development demonstrated that FTACPs could be directly quantified using the matrix signal as an internal standard. Direct MALDI-TOF quantification measured the model FTACP, poly(8:2 FTAC-co-HDA), to within 25% of the theoretical concentration in aqueous media.;Off gassing of residual fluorotelomer alcohols (FTOHs), and as the first degradation product of FTACPs supports atmospheric long-range transport (LRT) of volatile precursors as a principal mode for the global distribution of PFCAs. A collection of surface soils obtained from areas with little human impact showed PFCAs, as well as perfluoroalkanesulfonates (PFSAs), were distributed consistent with the atmospheric oxidation of volatile precursors.;The principle goal of this dissertation was to directly analyze FTACP degradation. The qualitative MALDI-TOF results strongly suggest that FTACPs will degrade under environmental conditions, and likely represent a significant indirect source of PFCAs.