Fluororubber composites: preparation methods, vulcanization mechanisms, and the associated properties

Fluororubber (FKM) is an irreplaceable sealing material that plays a critical role in new energy vehicles, petrochemical and aerospace industries. Their broad applications arise from the excellent thermal stability and solvent resistance of fluororubber. Despite there are increasing number of reports on preparation methods, properties and characterization of FKM in literature, there is still a lack of a thorough and comprehensive review that summarizes these results. This paper provides an overview of FKM types, preparation methods, property testing and microscopic characterization, and attempts to give a comprehensive introduction to the vulcanization mechanism of FKM using ternary fluororubber. The mechanical mixing method was identified as the most versatile preparation method in the review, but it is susceptible to causing agglomeration of nanomaterials. Furthermore, different vulcanization systems and reinforcing fillers can be chosen based on the application direction of FKM. Carbon nanomaterials with high inherent strength have the best reinforcing effect on FKM, although they also exhibit the most significant self-agglomeration effect. This can be mitigated through synergistic use of fillers of multiple dimensions and interfacial modification in future research. Additionally, current challenges and future prospects for FKM nanocomposites are also discussed.