CALENDAR AGEING OF ELECTRICALLY CONDUCTIVE CARBON BLACK: CHANGES IN PHYSICOCHEMICAL PROPERTIES AND POSSIBILITIES FOR FURTHER USE

The influence of calendar ageing of electrically conductive carbon black (CB) on its physicochemical and electrical properties, as well as on the physicomechanical and electrical characteristics of composites based on low-density polyethylene (LDPE), was studied. It has been established that calendar ageing of the electrically conductive CB of brand C140 (firm Omsk Carbon Group) leads to a change in the chemical composition of the surface, which causes an increase in electrical resistivity. Heat treatment of aged CB partially restores the chemical composition of its surface; however, the resistivity of aged CB is 16% higher than that of the original CB. Calendar ageing of CB reduces the effectiveness of its use as an electrically conductive filler for LDPE. The resistivity of a composite filled with 20 wt.% aged CB is 4 orders of magnitude higher than that of a composite filled with original CB. The mechanical characteristics of composites filled with aged CB pretreated with hydrogen peroxide are 1.8–7.9 times greater than those of composites filled with original CB