The low properties of recycled polymers associated with high cost of recycling hinder development of the thermoplastic recycling industry. Dynamic cross-linking of recycled thermoplastics with the formation of vitrimers enables superior mechanical properties, good reprocessability, and superior chemical and environmental resistance. Herein, a poly(ethylene-vinyl acetate) (EVA) vitrimer was formed by cross-linking with triethyl borate with the catalyst (bis(acetylacetonato)dioxomolybdenum(VI)). The resultant EVA vitrimer shows enhanced thermal stability and mechanical properties with up to two times improvement in Young’ modulus and storage modulus by comparison with the thermoplastic EVA. Moreover, 90% of Young’s modulus was maintained in the EVA vitrimer after five times of recycling, whereas only 72% can be maintained for recycling the thermoplastic EVA. This dynamic cross-linked EVA also exhibits superior UV and solvent resistance, which helps extend the service time of the recycled material. This work introduces a facile and efficient method to recycle and reuse EVA with low property loss. It has the potential to enable the production of high-performance EVA from EVA waste for different applications.

中文翻译：

---

通过动态交联回收具有改进性能的聚（乙烯-乙酸乙烯酯）

回收聚合物的低性能与高回收成本相关联，阻碍了热塑性回收工业的发展。再生热塑性塑料的动态交联以及形成三聚物的实现了卓越的机械性能，良好的可再加工性以及优异的耐化学和环境腐蚀性。在本文中，通过与硼酸三乙酯与催化剂（双（乙酰丙酮基）二氧钼钼（VI））交联来形成聚（乙烯-乙酸乙烯酯）（EVA）微晶聚合物。与热塑性EVA相比，所得EVA微晶纤维素显示出增强的热稳定性和机械性能，其杨氏模量和储能模量提高了两倍。而且，经过五次循环后，EVA振动器中仍保持了90％的杨氏模量，而只有72％的废料可以回收热塑性EVA。这种动态交联的EVA还具有出色的抗紫外线和耐溶剂性，有助于延长回收材料的使用寿命。这项工作介绍了一种简便，有效的方法来回收和再利用EVA，而损失的财产少。它具有使EVA废料生产出高性能EVA的潜力，可用于不同的应用。