The key difference between EPDM and Viton is that EPDM is useful in higher-temperature applications while Viton is useful in lower-temperature applications.
EPDM and Viton are important rubber materials with different applications at different temperatures. EPDM rubber is a type of synthetic rubber useful in many applications. Viton is a group of fluorocarbon-based fluoroelastomer materials that is commonly known as a fluorine rubber or fluoro-rubber.
CONTENTS
1. Overview and Key Difference
2. What is EPDM
3. What is Viton
4. EPDM vs Viton in Tabular Form
5. Summary – EPDM vs Viton
What is EPDM?
EPDM rubber is a type of synthetic rubber useful in many applications. The term EPDM stands for ethylene propylene diene monomer rubber. There are different types of dienes that can be used to manufacture EPDM rubbers, such as ethylidene norbornene, dicyclopentadiene, and vinyl norbornene.
Figure 01: Ideal Structure of EPDM Polymer
This material is an M-class rubber under ASTM international standard D-1418. This M class usually has elastomers consisting of a saturated chain of the polyethylene type. We can prepare EPDM rubber material from ethylene, propylene, and a diene co-monomer that can enable crosslinking via the sulfur vulcanization process.
Similar to other rubber materials, EPDM is also compounded with fillers, including carbon black and calcium carbonate, along with plasticizers such as paraffinic oils. It has useful rubbery properties that occur due to cross-linking. In addition to vulcanization with sulfur, crosslinking can also be achieved using peroxides or phenolic resins.
When considering the chemical and physical properties of EPDM rubber material, it has a hardness of 30 – 90 on the Shore A scale and tensile failure stress of 17 MPa. Its elongation after fracture is > 300% and the density is >2.00 g/cm3. Besides, there are some important thermal properties such as the coefficient of linear thermal expansion (106 micrometers), the maximum service temperature is 150 degrees Celsius, and the glass transition temperature is -54 degrees Celsius.
There are important uses of an EPDM rubber material, such as use in harsh external environments due to superior resistance to heat, light, and ozone exposure, useful as an electrical insulator, as a durable elastomer, useful to create weatherstripping, etc.
What is Viton?
Viton is a group of fluorocarbon-based fluoroelastomer materials that is commonly known as a fluorine rubber or fluoro-rubber. Viton is the brand name. This material is defined by ASTM International standard D1418 and ISO standard 1629. All the members in this group have vinylidene fluoride as a monomer. Originally, this material was developed by DuPont, which is made by many different companies today.
Depending on the chemical composition, there are different types of Viton polymers known as type-1, type-2, type-3, type-4, and type-5.
- Type-1 contains vinylidene fluoride and hexafluoropropylene. The fluorine content of this type is about 66% weight.
- Type-2 contains vinylidene fluoride, hexafluoropropylene, and tetrafluoroethylene. They have a higher fluorine content in their terpolymer form compared to the copolymer form.
- Type-3 contains vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene, and perfluoromethylvinylether. Fluorine content is typically ranging from 62 – 38% weight.
- Type-4 contains propylene, tetrafluoroethylene, and vinylidene fluoride. The fluorine content of this type is usually about 67 % weight.
- Type-5 contains vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene, perfluoromethylvinylether, and ethylene.
These compounds have an excellent high temperature and aggressive fluid resistance when compared to other elastomers. It can combine the most effective stability with many types of chemicals, such as oil, diesel, ethanol mix, or body fluid.
Viton is useful in chemical processes and petroleum refining, analysis and process instruments such as separators, diaphragms, cylindrical fittings, hoops, gaskets, etc., semiconductor manufacturing, food, and pharmaceutical industry, aviation and aerospace applications.
What is the Difference Between EPDM and Viton?
The key difference between EPDM and Viton is that EPDM is useful in higher-temperature applications while Viton is useful in lower-temperature applications. EPDM is a fluoroelastomer whereas Viton is an ethylene-propylene-diene-monomer.
The below infographic presents the differences between EPDM and Viton in tabular form for side-by-side comparison.
Summary – EPDM vs Viton
There are many uses of EPDM and Viton rubber materials. The key difference between EPDM and Viton is that EPDM is useful in higher-temperature applications while Viton is useful in lower-temperature applications.
Reference:
1. “All about EPDM Rubber – Properties, Applications and Uses.” Thomasnet® – Product Sourcing and Supplier Discovery Platform – Find North American Manufacturers, Suppliers and Industrial Companies.
Image Courtesy:
1. “EPDMcolorcoded” By Smokefoot – Own work (Public Domain) via Commons Wikimedia
2. “2021 Inko 14” By Ohlenhusen – Own work (CC BY-SA 4.0) via Commons Wikimedia