B-Oxidation

Friedrich, A 1975, in Houben-Weyl, Methoden der Organischen Chemie, Vol, IV/1 b Oxidation JI, p. 82, Thieme Stuttgart... 

Process. Any standard precursor material can be used, but the preferred material is wet spun Courtaulds special acrylic fiber (SAF), oxidized by RK Carbon Fibers Co. to form 6K Panox B oxidized polyacrylonitrile (PAN) fiber (OPF). This OPF is treated ia a nitrogen atmosphere at 450—750°C, preferably 525—595°C, to give fibers having between 69—70% C, 19% N density less than 2.5 g/mL and a specific resistivity under 10 ° ohm-cm. If crimp is desired, the fibers are first knit iato a sock before heat treating and then de-knit. Controlled carbonization of precursor filaments results ia a linear Dow fiber (LDF), whereas controlled carbonization of knit precursor fibers results ia a curly carbonaceous fiber (EDF). At higher carbonizing temperatures of 1000—1400°C the fibers become electrically conductive (22). 

Fig. 1. The H. C. Starck pyrometallurgical upgrading process of Ta—Nb-containing tin slags where the soHd vertical bars represent electrodes. The product of (a) electrothermic reduction of Sn slag goes to (b) oxidation of Fe alloy 20—60 Ta + Nb and then to (c) electrothermic reduction of oxidized Fe ahoy.

Kubaschewski, O. and Hopkins, B., Oxidation of Metals and Alloys, Butterworth, London (1%9)... 

The majority of potentiometric titrations involve chemical reactions which can be classified as (a) neutralisation reactions, (b) oxidation-reduction reactions, (c) precipitation reactions or (d) complexation reactions, and for each of these different types of reaction, certain general principles can be enunciated. 

Figure 3. 4f core level spectra for a series of glasses containing Ca, Za, or B oxide additives (glass sample F, G,... 

Figure 7.44 Thermal bond rupture (a) fragmentation reaction, (b) oxidation degradation.

Figure 17. Molecular motor reverse conformational changes (mechanical energy) stimulated by oxidation or reduction of the polymeric chain, a) reduced chain b) oxidized chain.

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