Effect of polymeric additives to coal tar pitch on carbonization behaviour and optical texture of resultant cokes

Abstract

Homogeneous compositions of coal tar pitch with 10% addition of various polymers were prepared under relatively mild conditions. The effect of a polymer on properties of composition and yield and optical texture of resultant semi-coke was assessed. There was no correlation between softening point or toluene insoluble content and carbonization yield. The addition of cumarone-indene resin, polystyrene, poly(ethylene-terephthalate), polypropylene and polysaccharide resulted in an increase in carbonization yield by 5–3%. Pitch-polymer compositions gave semi-coke of less homogeneous optical texture compared to parent coal tar pitch coke. Poly(vinyl chloride) was the only polymer which clearly improved the development of anisotropy on carbonization. The addition of polypropylene, polysaccharide and butadiene–styrene copolymer contributed to the deterioration of the optical texture.