Nitrile Rubber Encyclopedia

Influence of compounding system on vulcanization of nitrile reclaimed rubber peroxide vulcanizate

Create Date:2022-01-13 09:16:58Click volume:3249

Nitrile reclaimed rubber has excellent oil resistance, heat resistance and wear resistance. It can be used alone or in combination with nitrile rubber in an appropriate proportion to produce various oil-resistant rubber products, wear-resistant parts, etc., effectively reducing the cost of raw materials. When using nitrile reclaimed rubber or nitrile rubber/reclaimed rubber in combination to produce rubber products with high requirements for heat resistance and compression resistance, it is recommended to use peroxide vulcanization to reinforce the filling system, softening plasticizing system and anti-aging in the formula System design can affect the peroxide cure process.

1. Reinforcing filling system

When nitrile reclaimed rubber is vulcanized with peroxide, the pH value of the compounding agent in the reinforcing filling system has a great influence on the vulcanization of peroxide. Acidic fillers are easy to cause acid dissociation of peroxides, such as channel carbon black. , hard clay, white carbon black, etc., hinder the cross-linking effect. When acidic fillers must be used, alkaline substances such as paraffin can be added for neutralization, such as magnesium oxide, triethanolamine, diphenylguanidine and cyclohexamethyltetramine, etc. The addition of 1 part of magnesium oxide can have an obvious neutralization effect.

2. Softening and plasticizing system

In actual production, paraffinic paraffinic oils have little effect on the vulcanization of peroxides, while aromatic hydrocarbons and naphthenic oils will hinder the crosslinking reaction of peroxides; phenolic resins or acidic resins such as ancient Malon resin has adverse effect on peroxide vulcanization of nitrile reclaimed rubber 22LYY113. Therefore, when nitrile reclaimed rubber is cured by peroxide, it is generally recommended to use dibutyl phthalate.

3. Anti-aging system

Selecting a suitable rubber antioxidant can significantly improve the thermal oxygen aging resistance, ozone aging resistance and sunlight resistance of nitrile reclaimed rubber products. Among them, amine antioxidants, especially diamine antioxidants, have a great hindering effect on the cross-linking effect of peroxides, and phenolic antioxidants have less influence. Therefore, when nitrile reclaimed rubber is cured by peroxide, use antioxidant RD, antioxidant MB, antioxidant NBC, etc.; using 5 parts of zinc oxide, 2 parts of MB, and 0.5 parts of RD in the heat-resistant formula can obtain good protection. Effect.

Peroxide vulcanization will generate carbon-carbon crosslinks with high bond energy, which can give the vulcanizate good heat resistance. When nitrile reclaimed rubber is vulcanized by peroxide, the rubber product manufacturer must choose appropriate types of reinforcing agents, fillers, softening oils, plasticizers, antioxidants, etc., without affecting the effect of peroxide vulcanization. To improve the processing performance, physical and mechanical properties and aging resistance of nitrile reclaimed rubber products, the editor will continue to discuss related issues with you later.

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