Comparison of structure and properties of different brands of ethylene propylene diene monomer

Abstract

The microstructure, curing characteristics, physical and mechanical properties, wear resistance and aging resistance of eight brands of ethylene propylene diene monomer (EPDM) were compared. The results showed that the mass fraction of the third monomer vinylidene norbornene (ENB) in EPDM affected the curing rate of EPDM. Among the 8 brands, the curing rate of EPDM 9950 C was the fastest and that of EPDM 3722 was the slowest. The curing rate of oil filled EPDM 3666 was similar to that of EPDM with similar structure, but the maximum torque and minimum torque of EPDM 3666 vulcanizate decreased significantly. EPDM 6470 and EPDM 5890 F vulcanizates with high mass fraction of vinyl had higher tensile strength, modulus at 300% and Shore A hardness, and better tear resistance, wear resistance and resilience. The compression set of EPDM 9950 C and EPDM 4570 with higher relative molecular weight was the smallest, and the compression set of EPDM 3722 vulcanizate with more than 90% mass fraction of vinyl was the largest. The tensile strength and Shore A hardness of EPDM with small relative molecular weight and oil filled EPDM were lower. The aging resistance of eight brands of EPDM was good, among which EPDM 3722 with the lowest mass fraction of ENB had the best aging resistance.

Keywords

• ethylene propylene diene monomer
• curing characteristics
• physical and mechanical property
• wear resistance
• aging resistance