Influence of different external factors for the rubber sheet

Moisture. There are two main effects of moisture on rubber sheets: rubber sheets are left in humid air or immersed in water for a long time, which will cause damage to rubber plates. This is because water-soluble substances and hydrophilic groups in rubber dissolve in water. Especially after water immersion and air immersion, the damage of rubber will be accelerated under the alternate action of the two. However, in some specific cases, moisture not only does not damage the rubber, but it can delay the aging of the rubber sheet.

Ozone. Because ozone has a much higher chemical activity than oxygen, it is very damaging to rubber sheets. Like the principle of oxygen oxidation, ozone also causes the molecular chain to crack, but the effect of ozone on rubber changes with rubber deformation. When used as a deformed rubber, cracks perpendicular to the stress direction occur, so-called "ozone cracking". When acting on undeformed rubber, only an oxide film is formed on the surface without cracking.

Mechanical stress. Under the repeated action of mechanical stress, the rubber molecular chain breaks to form free radicals, and an oxidation chain reaction occurs, constituting a mechanochemical process. As for the molecular chain break and oxidation reaction, which is more intense depends on the environment in which the rubber sheet is located. In addition, cracks occur in the rubber sheet under stress.

Light. The shorter the light wave, the greater the energy. The energy of the outermost line is large, and the damage to the rubber plate is also great. In addition to directly leading to the cracking and cross-linking of rubber molecular chains, ultraviolet rays can also cause the rubber molecules dissociating, triggering and accelerating the oxidation chain reaction. The effect of light on the rubber sheet mainly occurs on the surface of the rubber sheet.

Heat. Excessive temperature will cause thermal cracking and thermal crosslinking of the rubber. However, the more serious consequence of high temperature is the aging of the rubber sheet. This is because the high temperature will accelerate the rate of oxygen expansion and oxidation, thereby accelerating the oxidation rate of rubber sheets, which is a common aging phenomenon-thermal oxygen aging.