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PусскийPeptizers serve as either oxidation catalysts or radical acceptors, which essentially remove free radicals formed during the initial
mixing of the elastomer. This prevents polymer recombination, allowing a consequent drop in polymer molecular weight, and thus the
reduction in compound viscosity.
What is the role of Peptizer during processing of natural rubber?
Peptizers serve as either oxidation catalysts or radical acceptors, which essentially remove free radicals formed during the initial
mixing of the elastomer. This prevents polymer recombination, allowing a consequent drop in polymer molecular weight, and thus the
reduction in compound viscosity. This polymer softening then enables incorporation of the range of compounding materials included in
the formulation. Examples of peptizers are pentachlorothiophenol, phenylhydrazine, certain diphenylsulfides, and xylyl mercaptan. Each
peptizer has an optimum loading in a compound for most efficiency.
Peptizers such as pentachlorothiophenol are generally used at levels between 0.1 and 0.25 phr. This enables significant improvement in
compound processability, reduction in energy consumption during mixing, and improvement in compound uniformity. High levels can,
however, adversely affect the compound properties, as excess peptizer continues to catalyze polymer breakdown as the product is in
service.
