Traceless metathetic degradation of waste vulcanized natural rubber with styrene as chain transfer agent in closed system

Abstract

The single-use personal protective equipment such as latex gloves causes severe pollution and resource waste. It is still a challenge to degrade waste vulcanized diene-based rubbers for chemical recycling. Here, the metathetic degradation of the waste vulcanized diene-based rubbers was investigated with latex gloves as an example with styrene and methyl acrylate (MA) as CTA in open or closed system, respectively. Traceless metathetic degradation was achieved with styrene in closed system, without any CTA residue in the degraded product, like ethenolysis. The traceless metathetic degradation mechanism was proposed as following: the self-metathesis of styrene was suppressed in closed system, the CTA residues in the end-capped products was eliminated by the cross-metathesis with the excessive styrene. Therefore, a mild “ethenolysis” was realized for the recycle of waste vulcanized natural rubbers in the production of new rubber products, regardless of CTA residues.