Thermal expansion and contraction are the objective laws of all substances in nature, and rubber is no exception. However, it must be considered that most rubber feet are not pure rubber, but various additives have been added, and the added ingredients will affect the shrinkage of rubber feet to varying degrees. That is to say,…
Molecular weight and molecular distribution of rubber
Natural rubber and synthetic rubber are typical polymer materials. Each molecule is made up of a number of structurally identical repeating units (links). For example, natural rubber is formed by the end-to-end connection of 1,4-isoprene units having the same chemical composition and spatial arrangement. However, low molecular weight materials have the same molecular weight per…
Type of rubber feets bonded to other materials
Most rubber feet are made of rubber and other materials (metal, fiber, plastic, etc.) by bonding and vulcanization. They are usually under external force when used. When the external force exceeds a certain limit, the bonding part will be destroyed. The use of rubber feets is lost, which is called “joint breakage.” In fact, this…
Stress relaxation of rubber feets
At a certain temperature and speed, during the process of stretching the unvulcanized rubber feet to a certain length, the internal stress generated will gradually decay to zero as time extends; but for vulcanized rubber, it will decay to a certain extent. It is terminated, as shown in Figure 4-15. This process is called stress…
Physical state of rubber
The movement of rubber molecular chains has multiple characteristics. Long chain molecules are composed of many repeating units. They have a connection to the side groups, some to the branches, and even the segments. In general, the molecular motion of rubber is not on the scale of the molecule as a whole, but in the…