The influence of stabilizers on mechanochemical processes in SBR rubbers
✍ Scribed by Rodoljub Ristić; Ljubica Vrhovac; Milenko Plavšić
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 247 KB
- Volume
- 72
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
Mechanochemical processes in commercial and model SBR rubbers containing different stabilizers were investigated. The influence of chemical structure and concentration of stabilizers in the temperature range from 20 -170°C and in the presence of air, i.e., under conditions similar to that in industrial processes, were studied. Stabilizers used were diaryl-p-phenylene-diamine, alkyl-aryl-p-phenylene diamine, polynuclear phenol, aryl-alkyl phenol, and alkyl-alkyl phenol. It was found that mechanochemical processes in SBR rubbers are less developed in the temperature region from 70 -130°C, so the influence of stabilizer is less expressive. During increasing temperature (130 -170°C) structure and concentration of stabilizers both show a strong influence on type and intensity of mechanochemical processes in SBR rubbers: pphenylene-diamines favor processes of linear degradation, while phenol stabilizers direct them toward branching and crosslinking, which is more expressed in the presence of aryl-substituted phenols than alkyl-substituted phenols. This fact is based on the differences in stability of free stable radicals of p-phenylene-diamines, alkyl-substituted phenols and aryl-substituted phenols. The fact that phenol stabilizers are involved in chain degradation as well as in branching and crosslinking processes during rubber processing, can be of high practical importance.
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