Metathetic degradation of waste vulcanized emulsion type butadiene-based rubber

Metathetic degradation has been recognized as promising strategy for the treatment of waste vulcanized rubbers as a Waste-to-Resources approach, not only eliminating the pollution but also recycling as resources. However, it was mainly used for the treatment of the waste vulcanized natural rubber, which contains plentiful cis -1,4- structure. Despite of a much higher consumption of the emulsion type butadiene-based rubbers than natural rubber, there was no report on the metathetic degradation of the waste vulcanized emulsion type butadiene-based rubbers due to their less cis -1,4- unit, although the metathetic functionalization of the nonvulcanized emulsion type butadiene-based rubbers have been well reported. Here, the metathetic degradation of waste vulcanized emulsion type butadiene-based rubber was explored with nitrile-butadiene rubber (NBR) glove as a model. Different from the metathetic degradation of waste vulcanized natural rubber via only cross metathesis between cis -1,4-structure and the chain transfer agent (CTA), the ring closing metathesis between the adjacent cis -1,4-structure and 1,2-structure also occurred in the metathetic degradation of waste vulcanized NBR. It is expected to open the door for the Waste-to-Resources approach of all waste vulcanized emulsion type diene-based rubbers.