ABSTRACT

A reprocessable elastomeric vulcanisate based on Epoxidised Natural Rubber with 50 mol-% epoxide content (ENR-50) was evloved by applying a self-assembled network based on thermochemically exchangeable ester crosslinks to the system. Hydrolysed Maleic Anhydride (HMA) as crosslinking substance in the presence of 1,2-DiMethylImidazole (DMI) as esterification accelerator and Zinc Acetate Dihydrate (ZAD) as transesterification catalyst was employed to generate the exchangeable ester crosslinking system. A sulphur-cured ENR-50 vulcanisate possessing a permanent sulphide crosslinking network was prepared as reference. Based on the results from cure characteristic and chemical structure analyses, the ENR-50 crosslinked with HMA behaves as a dynamic network because of a transesterification reaction catalysed by ZAD, promoting an exchangeable crosslinking network in the system. This dynamic network contributes to an intermolecular rearrangement of the ester crosslinking bonds at elevated temperatures, enabling interfacial self-adhesion and so reprocessability of the vulcanisates. The obtainable vulcanisates can be reprocessed, yielding relatively high retention of mechanical properties compared to their pristine counterpart. The interfacial self-adhesion and reprocessability of the vulcanisates have shown to significantly be improved with a higher loading of ZAD and elevated temperatures. This concept essentially shows a prospect towards developing e.g. novel recyclable and self-healing systems for elastomers.

摘要

通过将基于可热化学交换酯交联的自组装网络应用到系统中，开发出基于环氧化天然橡胶的可再加工弹性体硫化胶，环氧化物含量为 50 mol% (ENR-50)。在1,2-二甲基咪唑（DMI）作为酯化促进剂和乙酸锌二水合物（ZAD）作为酯交换催化剂存在下，水解马来酸酐（HMA）作为交联物质被用来生成可交换的酯交联体系。制备具有永久硫化物交联网络的硫磺硫化 ENR-50 硫化橡胶作为参考。根据固化特性和化学结构分析的结果，由于 ZAD 催化的酯交换反应，与 HMA 交联的 ENR-50 表现为动态网络，在系统中促进可交换的交联网络。这种动态网络有助于酯交联键在高温下的分子间重排，从而实现界面自粘合和硫化橡胶的可再加工性。获得的硫化橡胶可以进行再加工，与原始硫化物相比，机械性能保留率相对较高。硫化胶的界面自粘合性和可再加工性已显示出随着 ZAD 负载量的增加和温度升高而显着改善。这个概念基本上显示了开发例如用于弹性体的新型可回收和自修复系统的前景。实现界面自粘合，从而使硫化橡胶具有可再加工性。获得的硫化橡胶可以进行再加工，与原始硫化物相比，机械性能保留率相对较高。硫化胶的界面自粘合性和可再加工性已显示出随着 ZAD 负载量的增加和温度升高而显着改善。这个概念基本上显示了开发例如用于弹性体的新型可回收和自修复系统的前景。实现界面自粘合，从而使硫化橡胶具有可再加工性。获得的硫化橡胶可以进行再加工，与原始硫化物相比，机械性能的保留率相对较高。硫化胶的界面自粘合性和可再加工性已显示出随着 ZAD 负载量的增加和温度升高而显着改善。这个概念基本上显示了开发例如用于弹性体的新型可回收和自修复系统的前景。硫化胶的界面自粘合性和可再加工性已显示出随着 ZAD 负载量的增加和温度升高而显着改善。这个概念基本上显示了开发例如用于弹性体的新型可回收和自修复系统的前景。硫化胶的界面自粘合性和可再加工性已显示出随着 ZAD 负载量的增加和温度升高而显着改善。这个概念基本上显示了开发例如用于弹性体的新型可回收和自修复系统的前景。