Reasons for RB plastic products (rubber aging)

A) Oxygen, oxygen in the rubber shoe material has a free radical chain reaction with the rubber shoe material molecules, and the molecular chains are cracked or over-crosslinked, resulting in changes in the properties of the rubber shoe material. The oxidation effect is one of the important factors for the aging of rubber shoe materials one.

B) Ozone, the chemical active oxygen of ozone is much higher and more destructive. It also causes the molecular chain to crack, but the effect of ozone on the rubber shoe material is different depending on whether the rubber shoe material is deformed or not. When the effect is on When the deformed rubber shoe material (mainly unsaturated rubber shoe material) presents cracks that are straight to the direction of the stress effect, the so-called "ozone cracking"; Not cracked.

C) Heat: Increasing the temperature can lead to thermal cracking or thermal crosslinking of the rubber shoe material. But the basic effect of heat is still the activation effect. It is common to increase the oxygen diffusion rate and activate the oxidation reaction, thereby accelerating the oxidation reaction rate of the rubber shoe material. There is an aging phenomenon - thermal oxygen aging.

D) Light: The shorter the light wave, the greater the energy. It is the ultraviolet rays with higher energy that can damage the rubber shoe material. In addition to the ultraviolet rays that can directly cause the molecular chains of the rubber shoe material to crack and crosslink, the rubber shoe material absorbs light. Can produce free radicals, leading to and accelerating the oxidation chain reaction process. The external light plays a heating effect. Another feature of the light effect (different from the heat effect) is that it mainly grows on the surface of the rubber. The rubber content rate High sample, two sides will show network cracks, which is the so-called "optical outer layer crack";

E) Mechanical stress: Under the repeated effect of mechanical stress, the molecular chains of rubber shoe materials will be cracked to generate free quan, which will lead to oxidation chain reactions and form a mechanochemical process. Mechanical cracking molecular chains and mechanical activation oxidation processes. Which one can be dominant, Depending on the conditions in which it is located. In addition, it is easy to cause ozone cracking under stress.

F) Moisture: The effect of moisture has two aspects: rubber shoe materials are easily damaged when they are exposed to rain in humid air or soaked in water. This is because the water-soluble substances and clear water in rubber shoe materials are extracted by water. Caused by factors such as dissolution, hydrolysis or absorption. Especially under the replacement effect of water immersion and atmospheric exposure, it will accelerate the damage of rubber shoe materials. However, under certain conditions, moisture has no damaging effect on rubber shoe materials, and even has Delays the effect of aging.

G) Others: The effect factors on rubber shoe materials include chemical media, variable price metal ions, high-energy radiation, electricity and biology, etc.