Preparation of oil resistant and high‐temperature resistant <scp>NBR</scp> composites by chitosan/silica/coupling agent modification

Abstract In this paper, chitosan (CS), which is naturally degradable and low‐cost, was incorporated into nitrile butadiene rubber (NBR), the effects of chitosan amount on the properties of the NBR composites were investigated, and the optimal amount of chitosan was determined. On this basis, CS, silica and Si69 were modified by ball milling and plasma to prepare NBR composites with higher oil resistance and high temperature resistance. The results showed that the overall properties of NBR composites filled with 2phr CS is better. FTIR and SEM demonstrated the surface polarity of ball milling combined with plasma co‐modified CS/silica was weakened, the dispersion of fillers in the NBR matrix was promoted, the oil resistance and high‐temperature resistance of the composites were enhanced, the cross‐linking density and tear strength were improved by 28.12%, and 51.76% compared with that of the NBR composites without CS. The investigation on the oil and high‐temperature resistance of NBR composites for blowout preventer cores has been carried out, which promotes the development of blowout preventer cores toward high safety, low cost, and sustainability. Highlights The effect of chitosan amount on nitrile butadiene rubber (NBR) composites was explored. Chitosan, silica, and coupling agent were modified by ball milling and plasma. The oil and high‐temperature resistance of NBR composites were improved. The tear strength was increased by 28% under double destructive environment.