| 1. |
- 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)
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Performance and hazard assessment of fluorinated and non-fluorinated state-of-the-art DWR-polymers
- 2016
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Ingår i: SETAC Nantes 2016.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Durable water repellent (DWR) impregnation is applied in textile finishing to impart water and, depending on impregnation chemicals, oil and stain resistance to textiles. Following the phase-out of the mosteffective and predominating DWR-technology based on long-chain perand polyfluoroalkyl substances (PFASs), the textile industry had to find suitable alternatives. This phase-out has resulted in a market where bothfluorinated and non-fluorinated DWRs are available, dividable into three broad groups: short chain PFAS-based, silicone-based and hydrocarbonbased polymers. During our research in the SUPFES (Substitution of prioritised poly- and perfluorinated chemicals to eliminate diffusesources) project, the alternative DWRs were assessed with regards to: (i)their structural properties and connected performance, (ii) loss and degradation processes resulting in diffuse environmental emissions, and (iii) hazard profile for selected emitted substances. We worked withDWR-chemistry and raw material producers to appropriately treat two commercially relevant types of fabrics with the DWR alternative chemistries (fluorinated and non-fluorinated). We compared the performance of the treated fabrics developed in the project by testing the following properties using industrial standardised methods: generalproperties, physical properties, DWR properties and tabilities of properties considering relevant stress- parameters. We demonstrated that non-fluorinated alternatives can have a competitive water repellency incomparison to short-chain PFAS substitutes, but that they lack oil repellence. We further estimated possible loss mechanisms for impurities and/or degradation products from DWR-treated fabrics and conducted a hazard assessment for relevant chemicals based on data available in the literature. Our hazard ranking suggests that hydrocarbonbasedpolymers are the most environmentally benign, followed bysilicone- and fluorocarbon-based polymers. Future work will include risk assessment and life cycle assessments (LCA) to estimate long-term advantages and disadvantages of the different DWR-technologies.
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| 3. |
- Åkerfeldt, Maria, 1982, et al.
(författare)
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Textile piezoelectric sensors – melt spun bi-component poly(vinylidene fluoride) fibres with conductive cores and poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) coating as the outer electrode
- 2014
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Ingår i: Fashion and Textiles. - : Springer Science and Business Media LLC. - 2198-0802. ; 1:1
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Tidskriftsartikel (refereegranskat)abstract
- The work presented here addresses the outer electroding of a fully textile piezoelectric strain sensor, consisting of bi-component fibre yarns of β-crystalline poly(vinylidene fluoride) (PVDF) sheath and conductive high density polyethylene (HDPE)/carbon black (CB) core as insertions in a woven textile, with conductive poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) coatings developed for textile applications. Two coatings, one with a polyurethane binder and one without, were compared for the application and evaluated as electrode material in piezoelectric testing, as well as tested for surface resistivity, tear strength, abrasion resistance and shear flexing. Both coatings served their function as the outer electrodes in the system and no difference in this regard was detected between them. Omission of the binder resulted in a surface resistivity one order of magnitude less, of 12.3 Ω/square, but the surface resistivity of these samples increased more upon abrasion than the samples coated with binder. The tear strength of the textile coated with binder decreased with one third compared to the uncoated substrate, whereas the tear strength of the coated textile without binder increased with the same amount. Surface resistivity measurements and scanning electron microscopy (SEM) images of the samples subjected to shear flexing showed that the coatings without the binder did not withstand this treatment, and that the samples with the binder managed this to a greater extent. In summary, both of the PEDOT:PSS coatings could be used as outer electrodes of the piezoelectric fibres, but inclusion of binder was found necessary for the durability of the coating.
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