EPDM Rubber
The Properties and Uses of EPDM
(Ethylene Propylene Diene Monomer)
EPDM is a type of rubber that is classified as an elastomer. An elastomer is a polymer with elastic properties. This means the material will bend more under external stress than other substances. EPDM is also noted as a very reliable rubber because of its resistance to weathering and its resistance to water.
What is a Polymer?
To further understand how EPDM acts, we must first understand the basics. EPDM is a polymer, polymers are materials made up of many repeating molecules in order. Judging by how a polymer reacts on full scale, we can find out its small differences at the molecular level.
What are the different properties of rubber?
The different properties that are important in classifying a rubber include Youngs Modulus, Tensile Strength, Elongation, Hardness, Glass Temperature, Minimum/Maximum Service Temperature, and Density.
Youngs Modulus
The Youngs Modulus refers to a materials resistance to change in length. Specifically its resistance to that change while under lengthwise tension or compression. EPDM's Youngs Modulus measure is 6 MPa, meaning that up to 6 MPa of lengthwise tension or compression can be applied before it cannot return to its original length.
Tensile Strength
Tensile strength is the maximum load that a material can withstand before damaging. The Tensile strength for EPDM is 17.5 MPa.
Elongation
In materials science, elongation is measured using the stretch ratio (λ=l/L). The lower the number, the more apt to failing and breaking under stress, 0 is the "normal stretch ratio". The stretch ratio of EPDM is 3.75.
Hardness
Hardness refers to a materials resistance to deformation. The hardness of EPDM is 65 shore A, shore is a common hardness scale in materials science.
Glass Temperature
Glass temperature refers to the temperature at which a material goes from a hard glassy state, to a more malleable state. The glass temperature for EPDM is -54.5 Degrees Celsius.
Minimum/Maximum Service Temperatures
Minimum and maximum service temperatures are the lowest and highest temperatures at which a material can maintain its normal properties. The minimum service temperature for EPDM is -54 Degrees Celsius, and the maximum service temperature is 150 Degrees Celsius.
Density
Density is the measure of how compact a material is by measuring mass per unit volume. The density of EPDM is 1430 kg/cubic m.
EPDM's Resistance
EPDM is know for its exceptional resistant qualities, it is resistant to
weather aging, ozone, UV exposure, water, heat, dilute acids,
steam, animal and vegetable oils, alkalis, and brake fluids.
Uses
Because of its excellent resistant properties, EPDM is used in weather stripping and seals, and as seals for car doors and trunks. It is also used for tubing, water system O-rings and hoses, and wire insulation. I went to the Advanced Auto Parts on Merril Rd in Pittsfield, MA. They said that they carry EPDM seals, and that they are in high demand.
EPDM is also the type of rubber used in Flex Seal, the very popular, as seen on tv, liquid rubber in a can. It is mainly used as a sealant.
Works Cited
Osswald, Tim. “METHODOLOGY FOR GENERATION OF TIME-TEMPERATURE- TRANSFORMATION (TTT) DIAGRAM: SOLID AND CELLULAR EPDM.” Research Gate, Apr. 2013,
Jircitano, Alan J. “Intermolecular Forces.” ACID BASE INDICATORS.
Davidson, Ashlyn. “What's the Difference Between Silicone and EPDM? |.” Material Analysis & Materials Testing Lab, 29 Feb. 2016.
RubberCal. “What Is EPDM? A Brief Introduction.” RubberCal.
Advanced Auto Parts
BLÜCHER. “Material Properties of Rubber Seals.” BLÜCHER.
CROW. “EPDM - Ethylene Propylene Diene Rubber.” Polymer Properties Database.
ROGER, Josep. “EPDM Rubber.”
Bradford, Alina. “What Is a Polymer?” LiveScience, Purch, 13 Oct. 2017,
“EPDM (EN).” HDPE | Designerdata.