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.

中文翻译：

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苯乙烯为链转移剂密闭体系无痕复分解降解废旧硫化天然橡胶

乳胶手套等一次性个人防护用品造成严重污染和资源浪费。降解废弃硫化二烯基橡胶以进行化学回收仍然是一个挑战。在这里，以乳胶手套为例，分别以苯乙烯和丙烯酸甲酯（MA）作为CTA，在开放或封闭系统中研究废硫化二烯基橡胶的复分解降解。苯乙烯在封闭系统中实现了无痕复分解降解，降解产物中没有任何CTA残留，如乙烯醇分解。提出无痕复分解降解机理为：在封闭体系中抑制苯乙烯的自身复分解，通过与过量苯乙烯的交叉复分解消除封端产物中的CTA残留。因此，无论CTA残留如何，废旧硫化天然橡胶在新橡胶制品生产中的回收利用都实现了温和的“醇解”。