PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 12938548

Using hydrofluoroether solvents to replace HCFC-141b, Part I.

F Govaerts·D D Keane
View original source ↗Export metadata ↓

Abstract

Hydrochlorofluorocarbon solvents have been used for a variety of applications, including silicone deposition, precision cleaning, drying and tube swelling. Their use in these applications is banned in Europe from the end of 2001. Part I of this article explores the technical merits of replacement solvents, with particular reference to hydrofluoroethers.

Explore related subjects

ChlorofluorocarbonsCoated Materials, BiocompatibleEthersHydrocarbons, FluorinatedSolventsComparative StudyJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

F Govaerts, D D Keane. 2001. Using hydrofluoroether solvents to replace HCFC-141b, Part I.. https://pubmed.ncbi.nlm.nih.gov/12938548/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2005

An overview of environmental hazards and exposure risk of hydrofluorocarbons (HFCs).

Hydrofluorocarbons (HFCs) are being used as replacements for chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) that cause significantly stratospheric ozone depletion and global warming. HFCs under commercial uses as cleaning solvents in the electronic components, blowing agent in the foamed plastics, refrigerant in the air conditioning units and refrigerators, fire suppression agent in the fire protection, propellant in the metered dose inhalers (MDIs), and dry etching agent in the semiconductor manufacturing. Among these HFCs, 1,1,1,2-tetrafluoroethane (HFC-134a) is the most widely used one. From the environmental, ecological, and health points of view, it is urgent to mitigate and control the emissions of these HFCs from a diversity of commercial applications and industrial processes. This article aims to introduce these HFCs in commercial uses and environmental hazards (i.e., global warming, photochemical potential, flammability safety, environmental partition and ecotoxicity). Further, the updated data on the human toxicity, occupational exposure and health risk of these HFCs (esp., HFC-134a) are addressed in this review paper.

Chlorofluorocarbons↗
PubMed2005

Reductive dechlorination of chlorofluorocarbons and hydrochlorofluorocarbons in sewage sludge and aquifer sediment microcosms.

The reductive transformation of the 10 most-widely distributed fluorinated volatile compounds and of tetrachloroethene was investigated for up to 177 days under anaerobic conditions in sewage sludge and aquifer sediment slurries. Concentrations of parent compounds and of degradation products were identified by GC-MS. We observed transformation of CFC-11 to HCFC-21 and HCFC-31, of CFC-113 to HCFC-123a, chlorotrifluoroethene and trifluoroethene, of CFC-12 to HCFC-22, of HCFC-141b to HCFC-151b, and of tetrachloroethene to vinyl chloride and ethene. CFC-114, CFC-115, HCFC-142b, HFC-134a and HCFC-22 were not transformed. The results suggest that with both inocula studied here, hydrogenolysis is the primary reductive dechlorination reaction. CFC-113 was the only compound where a dichloro-elimination was observed, leading to the formation of chlorotrifluoroethene as temporal intermediate and to trifluoroethene as end product. The relative reduction rates of chlorofluoromethanes compared reasonably well with theoretical rates calculated based on thermochemical data according to the Marcus theory. Some of the accumulating HCFCs and haloethenes observed in this study are toxic and may be of practical relevance in anaerobic environments.

Chlorofluorocarbons↗