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- Schellenberger, Steffen, et al.
(författare)
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Highly fluorinated chemicals in functional textiles can be replaced by re-evaluating liquid repellency and end-user requirements
- 2019
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Ingår i: Journal of Cleaner Production. - : Elsevier Ltd. - 0959-6526 .- 1879-1786. ; 217, s. 134-143
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Tidskriftsartikel (refereegranskat)abstract
- Ongoing regulation of, and concerns regarding, per- and polyfluoroalkyl substances (also popularly known as “highly fluorinated chemicals”), has driven the textile market to search for sustainable alternative chemistries that can provide similar liquid repellency to per- and polyfluoroalkyl substances in performance textiles. This paper aims to inform the potential substitution of fluorochemicals with more environmentally friendly durable water repellents, taking a case-by-case approach and evaluating protection needs for consumer outdoor clothing and medical protective clothing separately. Recently developed non-fluorinated durable water repellents, some based on green chemistry principles, were evaluated in an in-depth assessment for their functionality against fluorinated short-chain alternatives (with hydro-and oleophobic moieties of carbon chain length of six or less). Repellency towards water and non-polar liquids was evaluated with established standard test methods and by measuring the roll-off angle of liquid droplets with a novel sample holder setup. This improved method allowed an enhanced mechanistic understanding of the droplets’ roll-off processes on woven textiles. The best non-fluorinated alternatives demonstrated high water repellency equal to fluorinated side-chain polymers with ‘short’ fluorinated carbon chains ≤6 carbons, and should be considered as suitable substitutes for consumer outdoor clothing. These results are supported by a survey of end-use requirements indicating water repellency and durability were the most important purchasing criteria. For polar liquids, with lower surface tensions, the repellency provided by non-fluorinated alternatives was clearly reduced, although they had a moderate repellency towards liquids with intermediate polarity (e.g. red wine or synthetic blood). Only fluorinated side-chain polymers with ‘short’ fluorinated carbon chains ≤6 carbons were seen to provide sufficient protection to polar liquids with very low surface tension (olive oil or gastric fluid). Since occupational protective clothing (e.g. medical clothing) often must provide protection against liquid of a wider range of polarities (e.g. in the case of medical clothing, to bodily fluids and protect the wearer from the transmission of diseases), current non-fluorinated DWRs do not provide sufficient liquid repellency. This implies that innovations in textile technology are still needed to substitute PFASs in some types of occupational protective clothing and other end uses where oil and stain repellency is essential.
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| 2. |
- Schellenberger, Steffen, et al.
(författare)
-
Release of Side-Chain Fluorinated Polymer-Containing Microplastic Fibers from Functional Textiles During Washing and First Estimates of Perfluoroalkyl Acid Emissions.
- 2019
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 53:24, s. 14329-14338
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Tidskriftsartikel (refereegranskat)abstract
- The quantity and composition of fibers released from functional textiles during accelerated washing were investigated using the GyroWash method. Two fabrics [polyamide (PA) and polyester/cotton (PES/CO)] were selected and coated with perfluorohexane-based side-chain fluorinated polymers. Fibers released during washing ranged from ∼10 to 500 μ with a similar distribution for the two textile types. The PA-based fabric released considerably more fibers >20 μm in length compared to the PES/CO-based fabric (>1000/GyroWash for PA vs ∼200/GyroWash fibers for PES/CO). After one GyroWash (2-15 domestic washes), fibers that contained approximately 240 and 1300 μg total fluorine per square meter (μg F/m2) were released from the PA and PES/CO fabrics, respectively. Current understanding of the fate of microplastic fibers suggests that a large fraction of these fibers reach the environment either in effluent wastewater or sewage sludge applied to land. In the environment, the fluorinated side chains will be slowly cleaved from the backbone of the side-chain fluorinated polymers coated on the fibers and then transformed into short-chain perfluoroalkyl acids. On the European scale, emissions of up to ∼0.7 t of fluorotelomer alcohol (6:2 FTOH) per year were estimated for outdoor rain jackets treated with fluorotelomer-based side-chain fluorinated polymers.
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