Engineering optimization of AOPOSS‑crosslinked FEPM composites for harsh environments

Abstract

This study systematically compared the performance differences of tetrapropylene fluororubber (FEPM) composites prepared by DCP/MAPOSS and DCP/AOPOSS crosslinking systems in acid, alkali and oil medium corrosion resistance. The results showed that the DCP/AOPOSS system exhibited better performance in thermal-oxidative aging resistance and oil corrosion resistance, while the DCP/MAPOSS system showed superior acid and alkali corrosion resistance, which was attributed to the protective effect of methyl groups on the R-based POSS side chains. In view of the comprehensive advantages of the AOPOSS system in crosslinking efficiency and oil resistance, engineering optimization was carried out in this research. The optimization strategy was to introduce a synergistic reinforcement system of N550 carbon black and silane-modified carbon nanotubes, aiming to develop a formula suitable for harsh oil and gas field environments. Systematic performance tests indicated that the optimized DCP/AOPOSS vulcanized tetrapropylene fluororubber material had high hardness (90 – 92 Shore A), high strength (≥ 27 MPa) and good toughness at room temperature. It showed excellent performance stability after 230 °C thermal-oxidative aging and long-term immersion in 150 °C oil medium, confirming its great application potential as a next-generation high-performance corrosion-resistant sealing material.