"Rubber aging" is a general term for all performance degradation of rubber products under long-term use.

"Sticky" is due to the oxidation reaction of rubber in the presence of oxygen, resulting in the increase of polar groups such as hydroxyl and carboxyl groups. These polar groups are the cause of stickiness. Generally speaking, it is equivalent to becoming self-adhesive.

In addition, the term "rubber" now often does not refer specifically to natural rubber, so it can be said that not all rubber products are easy to stick. Natural rubber is easy to stick because it contains a lot of carbon carbon double bonds, which is prone to oxidation reaction.

If it becomes sticky after contacting the solvent, the reason is that the components not involved in crosslinking in the rubber are dissolved. Rubber products are generally crosslinked. The crosslinked part is the main part of rubber. It only swells and does not dissolve under the action of solvent. If this is the case, it will not stick again after the solvent is dry.