Abstract
The optimal process conditions to achieve a high ratio of devulcanisation to polymer degradation have been searched for following tyre rubbers: SBR, BR, NR, and CIIR. These polymers all show their own particular breakdown characteristics. The temperature dependence of the breakdown mechanism was investigated by measuring sol fractions and crosslink densities. For SBR and BR, the highest reduction in crosslink density was found at a temperature of 220°C, together with a moderate increase in sol content. According to the Horikx theory, which correlates sol fraction and decrease in crosslink density, this is the result of a high degree of crosslink scission. Higher process temperatures result in a lower decrease in crosslink density due to recombination of active chain fragments. NR and CIIR show different behaviour. Breakdown of NR in this temperature range results in an almost complete destruction of the polymer network; crosslink density is reduced to almost zero and the sol fraction is close to 100 %. The same result is found for CIIR at still higher temperatures. Although different rubbers react via other devulcanisation mechanisms, the devulcanisation conditions for whole passenger car tyre material could be optimised.
Translated title of the contribution | Comparative investigation of the devulcanisation parameters of tyre rubbers |
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Original language | German |
Pages | 36-42 |
Number of pages | 7 |
Volume | 68 |
No. | 1 |
Specialist publication | Gummi, Fasern, Kunststoffe |
Publication status | Published - Jan 2015 |
Keywords
- NLA