Effect of Different R Reactive Groups on Cross-Linking Properties of POSS/Tetra-Fluoroethylene Propylene Composites

The C─F bond in the structure of Tetra-fluoroethylene propylene (TFEP) determines its good high temperature resistance and chemical stability, which makes this rubber widely used in the petrochemical industry. Compared with other rubbers, TFEP has high molecular chain stability and is not easy to cross-link. So, it suffers from low cross-linking efficiency and poor mechanical properties. The development of suitable cross-linking systems is significant to improve the performance of TFEP. Polyhedral oligomeric silsesquioxane (POSS) is widely used in composites because of its good thermal stability and mechanical properties. POSS-like materials have been widely used as cross-linking agents in the preparation of polymers, but their applications in fluoroelastomers are relatively few. In this paper, the effects of two different reactive functional groups of the R groups of POSS materials on the cross-linking behavior of TFEP are analyzed. We first optimized the formulation by vulcanization and mechanical property tests. Then, the type and dosage of the main crosslinking agent were optimized by vulcanization characteristic test, mechanical property test, and other characterization methods. The structures of the composites were characterized by IR spectroscopy and scanning electron microscope (SEM). Their mechanical and thermal properties were measured by tensile experiment, thermogravimetric analysis (TGA), and Differential Scanning Calorimetry (DSC) Analysis.