Research On High Temperature Medium Performance Of Modified NBR5080

In order to improve the high-temperature medium performance of nitrile rubber NBR5080, aviation nitrile rubber NBR5080 has been studied in the research. Nitrile rubber(NBR5080) and PTFE were treated by low temperature plasma(LTP) with different atmospheres, sealing material of NBR5080 coated with PTFE film was prepared. Accelerated aging experiment method was used to investigate the behavior of NBR5080 and modified NBR5080 which immersed in aviation kerosene RP-3, aviation lubricating HP-8B and the thermal oxidation environment. Physical, mechanical, thermal and surface properties were studied in three conditions environment. In addition, the service life of the two kinds of materials were predicted in RP-3, HP-8B and the thermal oxidation environment at 100 ℃.NBR5080 were treated with low temperature plasma. air, O2 and Ar were used as treatment media respectively. The results showed that Ar atmosphere treatment obtain better modification effect with treatment condition of 100 W、600 s、30 Pa, The water static contact angle of NBR5080 decreased from 91° to 25°, surface roughness increased from 16.37 nm to 97.78 nm. XPS showed that the surface of NBR5080 could form some polar species such as carbonyl, hydroxyl and carboxyl groups, peel strength of NBR5080 and PTFE increased from 0 N?m-1 to 44.2 N?m-1. In addition, the timeliness of plasma treatment was obvious after NBR5080 was taken out of plasma environment.NBR5080 and modified NBR5080 specimens were investigated after medium resistance experiment proceed with RP-3 and HP-8B. The results showed that due to the swelling effect caused of the oil medium, properties such as mass, size and compression deformation of NBR5080 increased. However, these properties of modified NBR5080 which tested with RP-3 and HP-8B had no evident change. The tensile strength, elongation at break and thermal properties of NBR5080 were decreased obviously. The tensile strength of modified NBR5080 decreased at early stage and increased slightly after 120 days later, elongation at break declined slowly relatively. Thermo Gravimetric showed that the high temperature properties of NBR5080 decreased with increasing of aging time. After immersed in mediums of RP-3 and HP-8B for 90 days, voids appeared on the surface of NBR5080, specimen tension fracture mode changed from ductile fracture to ductile-brittle fracture. The tension fracture of modified NBR5080 was still ductile fracture. The study on the aging behavior under thermal oxidation condition found that the mass、size of NBR5080 were decreased and the mass, size and hardness properties of modified NBR5080 remained stable. With the extension of aging time, the tensile strength of NBR5080 increased, and the elongation at break decreased significantly. The tensile strength of modified NBR5080 decreased first and then increased slightly and elongation at break declined slowly. The high temperature properties of NBR5080 decreased, while low temperature glass transition increased. However, the low temperature glass transition of modified NBR5080 decreased. The surface of NBR5080 appeared voids and the relative ratio of O elements increased first and then decreased with increasing of aging time. The tension fracture of NBR5080 changed from ductile fracture to brittle fracture. The tension fracture of modified NBR5080 was still ductile fracture after aging 120 days. NBR5080 tension fracture changed from ductile fracture to ductile-brittle fracture.The elongation at break was selected as performance evaluation index, the service life prediction of unmodified and modified NBR5080 been calculated with dynamic curve straight line plot method. Calculation results on specimen which tested at 100 ℃ obtained: unmodified NBR5080 life prediction results were 46.14 days, 50.63 days and 70.42 days which relative to RP-3, HP-8B and the thermal oxidation environment, Modified NBR5080 life prediction results were 123.98 days, 115.12 days, 124.66 days correspondingly.In a word, PTFE film modification method can prolong the service life of NBR5080 obviously. NBR5080 encapsulated by PTFE film could improve the high-temperature medium resistant significantly.