Study On Oil Resistant Sealing Ring Of Carboxylic Acrylic Rubber

When rubber material is used as oil resistant seal ring,it needs to have excellent oil resistance,heat resistance and aging resistance,and will not cause safety problems due to seal failure.Acrylic rubber not only has excellent performance as oil-resistant sealing ring,but also has the advantages of low price,environmental protection and no pollution.It is widely known as"automobile glue".In this paper,carboxylic acrylate rubber was studied.The results showed that the molecular weight of AR12 was similar to that of RK-0011,and the molecular weight of AR12 was higher than that of 220.AR12 has low Mooney viscosity,good low temperature resistance and good heat stability compared with two kinds of domestic carboxylic acrylate adhesive 220 and RK-0011.When evaluating the oil resistance of carboxylic acrylate rubber,it is proved that the one-dimensional solubility parameter has limitations in evaluating the oil resistance.The three-dimensional solubility parameter proposed by Hansen can be used to evaluate the oil resistance.There is an energy difference Ra between the rubber and the mixed solvent.The larger the Ra value is,the better the oil resistance is.The three-dimensional solubility parameters of AR12 were determined by swelling method,and then the experimental data were put into the Hansen solubility parameter software(HSPi P),which were?_d=18.30(MPa)1/2,?_P=7.10(MPa)1/2,?_h=60(MPa)1/2.It is proved that the three-dimensional solubility parameter is more accurate than the one-dimensional solubility parameter when evaluating the organic solvent resistance and oil resistance of acrylate compound.Finally,the formulation of carboxylic acrylic rubber AR12 was optimized,including the type of antioxidant,carbon black number and the amount of curing agent Diak-1.The results showed that the five antioxidants BLE,4020,N3100,RD and 445had little effect on the curing properties of acrylate compound,and the selected antioxidant 445 had good aging property and oil resistance for carboxylic acrylate compound.The change of antioxidant has little effect on the fatigue resistance of AR12.For AR12 after aging,antioxidant RD has better fatigue resistance.Four different brands of carbon black N220,N326,N330 and N375 have small particle size,high structure,high strength,high hardness and high compression properties,but they have good reinforcing effect and oil resistance.When the amount of curing agent is more than 0.5phr,1phr,1.5phr and 2phr,the internal crosslinking network density of carboxylic acrylate compound increases,the curing time is longer,and the mechanical properties are improved.However,the compression permanent deformation and hardness of the compound increase with the increase of the amount of curing agent.