Preparation And Properties Of Acrylate Rubber And Nitrile Rubber Alloy Elastomers

In this paper,nitrile rubber NBR was used to modify the blends of polyethylene-acrylate rubber AEM and polyacrylate rubber ACM respectively,and the vulcanization system of AEM and ACM mixed with NBR and its influence on the properties of vulcanized rubber were explored.A new macromolecule compatibilizer,graft copolymer(ACM-EPG)-g-(LX-NBR)was designed and synthesized to improve the compatibility of the rubber blend.The oil resistance,physical and mechanical properties and processability of the prepared acrylate rubber/nitrile butadiene rubber alloy elastomer are better than that of acrylate elastomer and heat resistance aging properties are superior to that of NBR.(1)The values of the solubility parameters of NBR,AEM,and ACM were estimated using Hansen's method theory.The results showed that the solubility parameters ? of the acrylate elastomers ACM,AEM,and NBR were similar,but their three-dimensional solubility parameters had hydrogen bonding components.The value ? was much larger than 2,and the kinetic compatibility was not good.(2)Using nitrile rubber(N220S)and ethylene-acrylate rubber AEM as raw materials,two independent vulcanization systems: sulfur carrier DTDM/TMTD/NOBS and peroxide DCP/HVA-2 were used to achieve good co-vulcanization between NBR and AEM.Six different blending ratios of AEM/NBR alloy elastomers were prepared.The results of DMA and TEM showed that AEM and NBR had the best compatibility at 90/10 ratio,and the torque difference of the alloy elastomer at this ratio was 16.1dN.m,the tensile strength reached 14.3MPa,the elongation at break reached 295.6%,and the mass and volume change rates after heat-resistant oil were 29.4% and 39.7%,respectively.(3)Using nitrile rubber(N220S)and acrylate rubber ACM as raw materials,two independent vulcanization systems,sulfur carrier DTDM/DM/NOBS and amine 1#vulcanizing agent/XL-60,were selected to achieve NBR/ACM with a good co-vulcanization property.Six different blending ratios of ACM/NBR alloy elastomer were prepared,and their compatibility was characterized by DMA and TEM.The results showed that the compatibility of ACM/NBR alloy elastomer at 90/10 ratio was better.The tensile strength was relatively low at 9.7MPa,but the oil resistance was significantly improved compared with theAEM/NBR combined rubber.The quality and volume change rates after heat resistant oil were 17.4% and 25.4%,respectively.(4)A macromolecular compatibilizer(ACM-EPG)-g-(LX-NBR)was designed and synthesized by in-situ grafting reaction.The compatibility of AEM/NBR(70/30)was characterized by DMA,SEM and TEM.It was found that the addition of compatibilizer reduced the phase domain size and improved the compatibility of the two phases.The effects of the amount of compatibilizer on the mechanical properties,heat aging resistance and oil resistance of AEM/NBR(70/30)blends were explored.The experimental results showed that the best compatibilizing effect was obtained when the content of compatibilizer was 5 phr.Compared with the system without compatibilizer,the tensile strength of the compatibilized AEM/NBR alloy elastomer increased from 9.7MPa to 13.1MPa,(performance increased by34.8%),and the tensile strength retention rate after heat aging increased from 118.1% to106.9%,the elongation at break retention increased from 58.8% to 73.0%,and the compression set rate decreased from 51.8% to 33.7%.