Tribology of rubber materials

The non-trivial mechanical properties of natural rubber, whether carbon black-filled or not, and of its synthetic counterparts in a variety of forms, mean that these particular materials are frequently used in everyday life, for their notorious stretchability (elastic bracelets, elastane fibers, chewing gum, turnbuckles, suspenders, garrots, bellows, bungee jumpers, etc.) and as various types of protection due to their impermeability to air and numerous fluids (oilskins, gloves, aprons, bibs, boots, raincoats, inner tubes, inflatable boats, preservatives, etc.).) and as protection against air and many fluids (oilskins, gloves, aprons, bibs, boots, raincoats, inner tubes, inflatable boats, condoms, hoses, children's balloons, pacifiers, etc.).

They are also used in the construction of mechanical components involving static contact, friction and rolling. Examples include seals, bridge bearings, anti-seismic bearings, rail pads, anti-skid end caps, damping blocks, tires of all shapes and sizes (skateboards, baby carriages, bicycles, motorcycles, passenger cars, vans, certain subways and tramways, heavy-duty vehicles, civil engineering equipment, aircraft, Formula 1 racing cars, etc.), transmission belts, wiper blades, wiper blades, wipers, etc.).), transmission belts, windscreen wiper blades, window cleaners, shoe soles, conveyor belts, bicycle brake pads, valve bodies, erasers, etc. These recent examples should not be forgotten. These recent examples should not obscure the fact that natural rubber from latex was known to Amerindian populations some thirty centuries ago.

The multiplicity of uses for rubber materials, both natural and synthetic, is obviously not accidental; it results from the surprising mechanical properties conferred on them by their particular chemical and macromolecular structures. Rubber materials are extremely flexible, capable of withstanding significant elongation at room temperature (up to seven times their resting dimension) and returning to their initial dimensions in a very short time. What's more, rubber materials have a very high coefficient of friction, which is why they are used in tire manufacture. In fact, it's the high level of friction between a tire's tread and the road surface that ensures the vehicle's roadholding.

After a brief review of the discovery and use of natural rubber by Amerindians some thirty centuries ago, and the introduction of its first synthetic counterparts, we describe the main volumetric and surface properties of rubber materials, which give them special tribological properties (adhesion, slipperiness, rolling and wear) used in the operation of many mechanical systems, particularly tires.