Tedlar

E. I. du Pont de Nemours Co., Inc. Fluoro Plastics Inc. Tedlar, Teftel, Teflon... 

Poly(vinyl fluoride) is available from Du Pont both as a resia and as transparent and pigmented films under the trademark Tedlar PVF film. Films are available ia nonoriented and oriented grade ia several tensile modifications and thicknesses, with either adherable or nonadherable release-grade surfaces. The 1992 prices ranged from 30 to 70/kg, vs 24 to 62/kg ia 1988. Prices for specially tailored films were significantly higher. 

Vinyl fluoride (fluoroethene), is manufactured from the cataly2ed addition of hydrogen fluoride to acetylene. It is used to prepare poly(vinyl fluoride) which has found use in highly weather-resistant films (Tedlar film, Du Pont). Poly(vinyhdene fluoride) also is used in weather-resistant coatings (see Eluorine compounds, organic). The monomer can be prepared from acetylene, hydrogen fluoride, and chlorine but other nonacetylenic routes are available. 

Poly(vinyl fluoride) was first introduced in the early 1960s, in film form, by Du Pont under the trade name Tedlar. Details of the commercial method of preparing the monomer have not been disclosed but it may be prepared by addition of hydrogen fluoride to acetylene at about 40°C. 

PVF has better heat resistance than PVC and exceptionally good weather resistance. It will bum slowly. Instability at processing temperatures makes handling difficult but this problem has been sufficiently overcome for Du Pont to be able to market their Tedlar film. 

Other fluorine-containing plastics These materials, in general, attempt to compromise between the exceptional end-use properties of p.t.f.e. and the processability of ordinary thermoplastics. Examples include polychlor-trifluorethylene, tetrafluorethylene-hexafluorpropylene copolymers (FEP resins) and polyvinylidene fluoride. Polyvinyl fluoride is available in film form (Tedlar) with excellent weathering resistance. 

Exhaled air Collected in Tedlar bag injected into GC GC/ECD (both trichloro- ethylene and trichloro- ethanol) 5 ppb (trichloroethylene) 2 ppb (trichloro-ethanol) NR Monster and Boersma 1975... 

Figure 1 Schematic diagrams of (a) stainless steel air sampling canister and (b) Tedlar bag...

Technora fiber, 13 376-377 TechStreet technical information superstore, 15 763 Tecnoflon, 7 641 Tecomanine, 2 101 Tectosilicates, 22 453t Tedisamil, 5 106 Tedlar PVF film, 20 592 Teflon... 

Air in the community was sampled for VOCs by Summa canister (8-hour orifice, and 7 m stainless steel frit filter) and for reduced sulfur gasses by Tedlar bag. These samples were 24 hour express mailed to Performance Analytical Inc. and analyzed as described above. Aerosols (PM2.s and PMi0)... 

A Tedlar bag, made of polyvinyl fluoride, was used. These bags were purchased from SKC, Inc. (US). 

Allene must not be allowed to condense in the reaction vessel prior to the introduction of the BBr3. Boron tribromide reacts rapidly and exothermically with liquid allene to give a black mixture that yields very little of the desired product. In one experiment in which the connection between the Tedlar bag and the reaction vessel... 

The olfactometer was calibrated using C02, as the odorous gas, diluted in air to 10000 ppm by volume, and contained in a 30 1 Tedlar bag (Fig. 5) (7). C02-free oxygen was used as the diluting gas. The C02 concentration was was sufficiently low to avoid significantly altering the density of the odorous air. The bag was connected by silicon rubber tubing to the rotameter inlets and the diluted gas mixture was sampled via a tube placed inside the nose-piece and analysed by an infra-red gas analyser, with an accuracy of greater than 1% (Fig. 5). 

The recommended standard method evolved is therefore as follows. The apparatus consists of flowmeters, two 1 1 glass cylinders in series and an odour sampling bag of Tedlar , connected with PTFE tubing as shown in Fig. 1. The air used is oil- and odour-free and preferably from a compressed air cylinder. The air stream splits in two so that the diy air mixes with the humid air that has passed through the sludge, so as to prevent condensation in the odour sampling bag. 

In the case of static sampling, the material of the bag should have the same properties as given before and, moreover, should suffer no sample losses by diffusion. Good experiences have so far been made with PFTE, TEDLAR and Polyamid bags. 

Exhaled air (breath) Collection in Tedlar bag preconcentration by Tenax-GC thermal desorption HRGC/FID and HRGC/MS No data No data Krotoszynski et al. 1979... 

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