CORRELATION BETWEEN CROSS-LINK DENSITY AND PROPERTIES OF RUBBER CONTAINING CHEMICALLY-MODIFIED CARBON-BLACK

A surface modification process on carbon black N-330 was carried out i n a stream of deoxidised inert gas vapours of sulfurating agents S8, C S2, SO2 and H2S at 873 K. Total hydrogen, oxygen and even carbon decre ase with the increase of sulfur deposited on the carbon surface. The d ensity of crosslinks of vulcanisates increased with amount of bound su lfur and they have greater strength properties than with commercial ca rbon black.The study of the modified carbon black by means of scanning electron microscopy proves that only in case of modification by eleme ntary sulfur in deoxidised N2 have been formed ''whiskers'' (L/D almos t-equal-to 40), on 10% of the inspected surface area. Vulcanisates con taining modified carbon black have a different network structure.