Fibers mechanically high-quality

High aromatic PODA t5 es, such as poly(p-phenylene-l,3,4-oxadiazole), can be graphitized to yield a high quality graphite." The graphitization takes place at 2,800-3,000°C. From a heat-treated PODA film at 3000°C, an electrical conductivity of 1.4—1.8 10" Scm has been obtained. Graphite fibers with excellent mechanical properties have been obtained. 

Mercerization is the most common method to produce high-quality fibers (Ray et al. 2001). Scheme 1 shows the probable mechanism of mercerization of cellulose fibers. Mercerization leads to fibrillation, which causes breaking down of the composite fiber bundle into smaller fibers. Mercerization reduces fiber diameter, which leads to the development of a rough surface topography, resulting in better fiber-matrix interface adhesion and improved mechanical properties (Joseph et al. 2000). Moreover, mereerization increases the number of possible reactive sites and allows better fiber wetting. 

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