INFLUENCE ON FRICTION FORCE OF ADHESION FORCE BETWEEN VULCANIZATES AND SLIDERS

The effects of vulcanizate and slider surface free energy-as well as t he adhesion force (P) between them-on friction the force (F) and the c oefficient of friction (mu) has been investigated. SBR and NBR vulcani zates were prepared using three molds differing in surface free energy . The mold with a high surface free energy gave a vulcanizate surface possessing polar groups. The mold with low surface energy gave a vulca nizate surface with many nonpolar groups. The coefficient of friction increased with the surface free energy of SBR and NBR vulcanizates. Wi th SBR vulcanizate (surface free energy, 31.3 mJ.m(-2)) and teflon sli der (surface free energy, 28.1 mJ.m(-2)) combination having the least surface free energy, the coefficient of friction was constant at great er than a 0.2N load. With vulcanizates and an aluminum slider with hig h surface free energy, friction force could be detected even at zero l oad because of the adhesion force at the interface: Friction force inc reased linearly with adhesion force between vulcanizates and sliders w hen the physical properties of the vulcanizates and net work chain den sity were constant. The present results clearly demonstrate the contri bution of adhesion force to the friction of vulcanizates.