Mechanical and abrasion wear properties of hydrogenated nitrile butadiene rubber of identical hardness filled with carbon black and silica

Abstract

The mechanical and abrasive wear properties of a hydrogenated nitrile butadiene rubber filled with 35 part per hundred rubber carbon black or silica with and without silane surface treatment (SI-si and SI, respectively), were investigated. Specimens were subjected to dynamic mechanical thermal analysis (also to study the Payne effect), mechanical (hardness, tensile modulus, ultimate tensile strength and strain, Mullins effect and tear strength), and fracture mechanical (J-integral) tests. The abrasive coefficient of friction and wear (specific wear rate, W_s) of the hydrogenated nitrile butadiene rubbers of identical hardness were measured against abrasive papers of different grit sizes (P600-P5000).The worn surface of the HNBR systems was inspected in scanning electron microscopy and the typical wear mechanisms deduced and discussed. Coefficient of friction did not change with the grit size by contrast to W_s which was markedly reduced with decreasing surface roughness of the abrasive paper. W_s of the compounds did not vary when wearing against P3000 and P5000 abrasive papers, representing mean surface roughness values of 7 and 5 μm, respectively. This was attributed to a change from abrasion to sliding type wear. hydrogenated nitrile butadiene rubber- carbon black outperformed the silica filled versions with respect to W_s though exhibited the highest coefficient of friction. No definite correlation could be found between the abrasive wear and the studied dynamic mechanical thermal analysis and (fracture) mechanical properties.