Pitch feedstock properties

This profile addresses the toxicological and toxicokinetics database for several substances, wood creosote, coal tar creosote, coal tar, coal tar pitch, and coal tar pitch volatiles, whose production stems from the incomplete combustion or pyrolysis of carbon-containing materials. Creosotes, coal tar, coal tar pitch, and coal tar pitch volatiles are composed of many individual compounds of varying physical and chemical characteristics. In addition, the composition of each, although referred to by specific name (e.g., wood creosote or coal tar creosote) is not consistent. For instance, the components and properties of the mixture depend on the temperature of the destructive distillation (carbonization) and on the nature of the carbon-containing material used as a feedstock for combustion. 

In addition to the process parameters, the quality of the fiber depends on the properties of the feedstock. In particular, mild hydrogenation of the pitches... 

Carbon fibers are made from many different feedstocks. The most important commercial fiber is made from polyacrylonitrile (PAN). It is four times stronger than steel, the same modulus or higher, and does not fail in creep or fatigue. These properties made the fiber attractive for aerospace applications initially, and later for sporting and industrial applications. Another important feedstock is pitch from refinery or steel-making operations, which leads to fibers with very high modulus and thermal and electrical conductivities. Properties of the fibers, and critical steps in their manufacture are described, together with structural characteristics and failure mechanisms. 

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