Rubber Chem Encyclopedia

The antagonistic, additive and synergistic effects of commonly used reclaimed rubber antioxidants

Create Date:2022-06-06 14:27:23Click volume:2991

When using reclaimed rubber to produce rubber products, rational use of rubber antioxidants can significantly prolong the service life of rubber products. In the production of different reclaimed rubber products, some products use a certain antioxidant alone, and most reclaimed rubber products use two or more antioxidants together. Why? This is mainly because different types of antioxidants will have different effects when used at the same time, mainly including the following three types: antagonistic effect, additive effect and synergistic effect. The editor will discuss these three effects with you today.

1. The antagonistic effect of rubber antioxidants in reclaimed rubber products

The so-called antagonistic effect among rubber antioxidants, that is, the protective effect of two or more antioxidants when used together is less than the sum of the effects when they are used alone. This phenomenon must be avoided when using reclaimed rubber 2ELYY66 to produce rubber products. In actual production, the combination of generally acidic antioxidants and alkaline antioxidants will produce complexes similar to salts, and then produce antagonistic effects; chain scission antioxidants and certain sulfides, especially polysulfides There may also be confrontational effects.

For example: when natural rubber/latex reclaimed rubber is used in combination to produce rubber products, when 4010NA is used as an antioxidant, the oxidation speed is increased after adding polysulfide, that is, a counteracting effect is produced. Carbon black is the most commonly used reinforcing agent for reclaimed rubber products. In reclaimed rubber, it can not only inhibit oxidation, but also help oxidation; in the presence of chain scission antioxidants, the inhibitory effect of carbon black is reduced, and in the presence of carbon black The protective effect of antioxidants is reduced, which is also a counteracting effect.

2. The additive effect of rubber antioxidants in reclaimed rubber products

The additive effect of rubber antioxidants, that is, the protective effect produced by the combined use of the antioxidants is equal to the sum of the effects of their respective use alone. The additive effect is the basic requirement for the selection of antioxidants for reclaimed rubber products. The use of the same type of anti-aging agent generally only produces additive effects, but sometimes other effects are also produced.

For example: when two phenolic antioxidants with different volatility are selected in the reclaimed rubber product, the antioxidant can not only produce an additive effect in the reclaimed rubber, but also can be used in a wider range than the same amount of a single antioxidant. Exhibits inhibitory effect within the operating temperature range. When choosing the commonly used antioxidants for reclaimed rubber products, the combination of several antioxidants at a lower concentration can effectively avoid the phenomenon of pro-oxidation when most antioxidants are used alone at a higher concentration, and the combined effect is better.

3. Synergistic effect of rubber antioxidants in reclaimed rubber products

The synergistic effect of rubber antioxidants, that is, the protective effect of the combined use of the antioxidants is greater than the sum of the effects of each antioxidant used alone. In actual production, the synergistic effect of antioxidants can be divided into non-uniform synergistic effect (the synergistic effect produced by the combined use of two or more antioxidants acting according to different mechanisms) and uniform synergistic effect (two or more antioxidants) The synergistic effect produced by the combined use of antioxidants that work with the same mechanism).

The synergistic effect of chain scission-type antioxidants and ultraviolet absorbers, metal ion passivators, and antioxidants that inhibit ozone aging is a non-uniform synergistic effect (hetero synergistic effect). For example, antioxidant D and antioxidant WSP can produce synergistic effect with antioxidant MB; antioxidant 2246, antioxidant 4010 and antioxidant DLTDP can produce synergistic effect in DCP vulcanized natural rubber/latex reclaimed rubber combined rubber.

When using reclaimed rubber to produce rubber products, rubber product manufacturers must choose appropriate rubber antioxidants to further extend the service life of rubber products while reducing costs. The editor will continue to discuss related issues with you later.

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