Polytetrafluoroethylene foils

Polypropylene (PP) films (100 pm from GoodfeUow, UK, or 300 pm from Ciba-Geigy, Switzerland) as well as polytetrafluoroethylene (PTFE) foil (1 mm from DuPont, USA) were ultrasonically cleaned in a diethyl ether bath for 15 min. The monomers used were acrylic acid, aUyl alcohol, and aUylamine (aU >99%... 

Polytetrafluoroethylene, PTFE. Applications molded articles, foils, flexible tubing, coatings, jackets, sealings, bellows, flasks, machine parts, semifinished goods, printed networks. 

In this method an extruded film or foil made from a partially crystalline polymeric material (polytetrafluoroethylene, polypropylene, polyethylene) is stretched perpendicular to-the direction of the extrusion, so that the crystalline regions are located parallel to the extrusion direction. When a mechanical stress is applied small ruptures occur and a porous structure is obtained with pore sizes of about 0.1 pm minimum to a maximum of about 3 pm maximum. Only (semi) crystalline polymeric materials can be used for this technique. The porosity of these membranes is much higher than that of the membranes obtained by sintering, and values up to 90% can be obtained. 

After drying, paste the counter electrode on the bottom surface of the sensor foil. With two wires attached to the eonductive ink electrodes, the sensor is ready for use. To illustrate how the sensor measures force or force rate, we have applied a mechanical force to the sensor element, with a pressurized polytetrafluoroethylene (Teflon) bar (Fig. 6 Dansaehmiiller et al. 2005). 

Indole 83 A 75-mL glass vial with a polytetrafluoroethylene (PTFE)-lined cap was charged with compound 81 (4.84 g, 12.5 mmol, 2.0 equiv), compound 82 (4.0 g, 6.25 mmol, 1.0 equiv), Pd(OAc>2 (280 mg, 1.25 mmol, 20 mol%), AgOAc (1.56 g, 9.4 mmol, 1.5 equiv), and 12 mL of -BuOH. The reaction vial was capped, covered with aluminum foil, and heated at 110°C for 36 hours. The reaction mixture was then cooled to room temperature, diluted with 10 mL dichlorome-thane, filtered through Celite (Sigma-Aldrich), concentrated under vacuum, and purified by flash chromatography (20-40% ethyl acetate in hexane) to give compound 83 (4.78 g, 85%) as an off-white solid. 

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