Thread Content
Rubber is one of the very important and widely used industrial materials. According to incomplete estimates, China’s total rubber consumption in the year 2000 will reach 2.2 million tons. Tribological properties are a crucial indicator for rubber products; examples include the wear resistance, braking performance, and driving efficiency of rubber tires, as well as the wear resistance of seals. Improving the wear resistance and service life of rubber products can bring considerable economic and social benefits in terms of energy, materials, lubricants, and other resources. Rubber is a material with a very low elastic modulus and high viscoelasticity; therefore, its friction exhibits characteristics different from those of metals and ordinary polymers. The interaction forces between rubber and a rigid surface at the sliding contact interface include adhesion and hysteresis; the friction force is also composed of these two components: F = Fa + Fh, where Fa represents the adhesive friction force and Fh represents the hysteresis friction force. Adhesive friction results from the continuous formation and breakdown of adhesion between the rubber and the counterface, while hysteretic friction is caused by energy dissipation during the periodic deformation of the sliding rubber block due to surface asperities. When rubber slides on a hard and smooth surface, the friction force is primarily of the adhesive type. According to the adhesive theory of elastomer friction, the adhesive friction force Fa can be expressed as: Fa = K1S(Er/pr) tanδ(r