Cohesion and Toughness Improvement of Pitch Binder by Thermosetting Resin Modification for TiB₂/C Composite Cathode

Furan, epoxy, and their composites were used to modify pitch binder for TiB₂/C composite cathode in aluminum electrolysis. The physical-chemical properties of the cathodes have been investigated. When the pitch is modified by furan and epoxy composite, the cathode exhibits the lowest electrolysis expansion (0.60 pct), open porosity (28.80 pct), and electrical resistivity (35.91 μΩ·m); the highest bulk density (2.54 g·cm^–3); and compressive strength (44.90 MPa). Results of the semicokes from a scanning electron microscope show that cohesion and toughness are effectively improved, especially in the case of the furan and epoxy composite-modified pitch semicokes. Studies using Fourier transform infrared spectroscopy indicate that an aromaticity index of 0.845 and a condensed degree Abs₈₈₀/Abs₁₆₀₀ of 0.927 of polynuclear aromatic hydrocarbons are obtained, suggesting that a more complete reaction of the cross-linked curing takes place in the pitch binder modified by furan and epoxy composite, which improves cohesion and toughness of the binder and, thus, enhances the performances of TiB₂/C composite cathode.