DuPont’s AEM rubber is divided into binary and ternary adhesives, which are composed of ethylene (E)/methyl acrylate (MA), and ternary adhesives are composed of E/MA/monomers that provide vulcanization positions (CS). The binary rubber can only be vulcanized using peroxide, while the ternary rubber can be vulcanized using amine vulcanizing agents because it contains a third monomer that provides the vulcanization position. When used for continuous vulcanization of cables using high-pressure steam, the ternary rubber can also be vulcanized using peroxide.
Here are 4 characteristics for AEM Rubber:
(1) The thermal aging performance
This is measured by a 50% reduction in elongation at break. AEM can be used continuously at 120 ℃ for 18 months and 170 ℃ for 6 weeks. The thermal aging properties of AEM are significantly superior to chlorosulfonated polyethylene rubber (CSM) and NBR.
(2) Liquid resistance
AEM has good resistance to ATF (automotive automatic steering fluid), gear oil, ethylene glycol/water mixture, diesel and kerosene, but has poor resistance to fuel C, phosphate ester hydraulic oil, non mineral brake fluid, esters, ketones, and gasoline.
(3) Cold Resistance
AEM has a better cold resistance than ACM and can be used at – 40 ℃. If appropriate plasticizers are added, it can also maintain softness at lower temperatures.
(4) Compression set resistance
AEM terpolymer vulcanized with amine curing agents has excellent compression set resistance at 170 ℃ × At 70 h, the compression set is less than 20%, but the compression set resistance of the binary rubber vulcanized with peroxide is slightly poor. The long-term compression set test shows that AEM has excellent compression set resistance, and the compression set resistance of the ternary adhesive is equivalent to that of HNBR.
In addition, AEM has excellent ozone resistance and weather resistance. After 3 years of exposure, its appearance and physical properties have almost no change. AEM ternary adhesive has excellent flex resistance, with a flex life of more than 250000 times at 100 ℃, but the flex resistance of binary adhesive is slightly poor.
More about AEM you need to learn
The AEM added with aluminum hydroxide has good combustion safety performance, especially with extremely low smoke emission and corrosive gas emission during combustion. The dynamic performance of AEM is also good, and its shock absorption performance at high temperatures is close to that of IIR.
Due to its excellent performance, AEM has been listed as an EE material in ASTM D 2000, “Standard Classification System for Rubber Products in Automotive Applications“. EE material refers to a material with a heat resistance level of 175 ℃ and a volume change rate of no more than 80% after immersion in IRM 903 # oil (formerly 3 # standard oil) at 150 ℃ for 70 hours. At the same time, AEM has been listed in the SAE J200 standard, indicating that AEM has been recognized in the field of automotive accessories in the United States.
The main application fields of AEM are automotive accessories, such as front and rear crankshaft oil seals, front and rear spindle oil seals, power steering pump seals, transmission pump seals, water pump seals, engine valve stem oil seals, CVJ dust shields, power steering hoses, and 175 ℃ grade radiator hoses. In addition, AEM has a good application prospect in the field of halogen-free low smoke flame retardant cable sheath.