Adhesive modifiers for bitumen obtained from coumarone-indene fractions of liquid coal coking products

Modifiers are added to road bitumens to enhance their properties. The only significant disadvantage of current industrial modifiers is their relatively high cost. The authors develop a new way to solve this problem by using relatively cheap raw materials for obtaining effective adhesive modifiers for bitumen, namely, coal coking liquid products. Therefore, coumarone-indene resin (CIR) and coumarone-indene-carbazole resin (CICR) were obtained by ionic co-oligomerization based on fractions extracted from liquid products of coal coking (gasoline fractions and coal tar). When added in an amount of 7 wt%, CIR increases temperature resistance and doubles the adhesive properties of bitumens. However, CIR degrades the plasticity of bitumens, so to produce polymer-modified bitumen (PMB) cheap plasticizers (petroleum tar and resin from the decomposition of the organic mass of brown coal) must be used. CICR has practically no effect on the temperature resistance of bitumens, slightly improves their plasticity, and doubles the adhesion to glass at a content of 1 % wt.%. The CIR and CICR use will make it possible to obtain relatively inexpensive PMB.