What is the Difference Between FKM and FFKM

FKM and FFKM are two polymers. Polymers are made of repeating units. They are used in many industries to manufacture products. 

What is the difference between FKM and FFKM? FFKM has a higher fluorine content than FKM. 

Key Areas Covered

1. What is FKM 
      – Definition, Features
2. What is FFKM
      – Definition, Features
3. Similarities Between FKM and FFKM
      – Outline of Common Features
4. Difference Between FKM and FFKM
      – Comparison of Key Differences
5. FAQ: FKM and FFKM
      – Answers to Frequently Asked Questions

Key Terms 

FKM, FFKM

What is FKM 

FKM is a fluoroelastomer that is a synthetic rubber. It is a fluorocarbon-based material containing a higher number of fluorine atoms.

The primary monomer used in FKM production is tetrafluoroethylene (TFE). Other fluorinated monomers that may be used include hexafluoropropylene (HFP), vinylidene fluoride (VDF), and perfluoroalkyl vinyl ethers (PAVE).

The basic structure of FKM has repeating carbon units with two fluorine atoms attached to each carbon. The polymer chains are usually crosslinked to increase their properties. Crosslinking agents used in FKM production can include peroxide, bisphenol A, and dicumyl peroxide.

FKM has high temperature resistance. It can withstand temperatures in the range from -40°C to 250°C. It is also highly resistant to certain types of chemicals, such as fuels, oils, greases, and many solvents. Moreover, it is resistant to ozone and UV radiation.

FKM is used in various industries. FKM is used in components such as engine seals, fuel system components, brake systems, O rings and seals, gaskets in aircraft engines, and  fuel systems. It is also used in chemical processing plants.

What is FFKM

FFKM, or perflouroelastomer, is a family of elastomers. The main components of FFKM are fluorinated monomers, copolymers, and curing agents. Monomers, such as perfluoropropylene (PFP) and perfluorovinyl methyl ether (PFVME), form the backbone of the polymer chain. Chemical resistance and temperature stability of the material are due to the fluorine atoms present. FFKMs often incorporate copolymer units, such as perfluoromethyl vinyl ether (PMVE) or perfluorobutyl vinyl ether (PFBVE). Curating agents are added in the manufacturing process of FFKM to crosslink polymer chains and to get elastomeric properties.

FFKM has a highly fluorinated polymer backbone. The polymer chains are crosslinked together to form a three-dimensional network. 

FFKMs can withstand extremely high temperatures exceeding 300°C. FFKM has a low gas permeability due to the dense molecular structure.

FFKM has many industrial applications. They are used in O-rings, seals, and gaskets in aircraft engines, fuel systems, and hydraulic components, downhole equipment, seals, and gaskets in the oil and gas industry and  cleanroom equipment, valves, and seals.

Similarities Between FKM and FFKM

• Both FKM and FFKM are highly resistant to a wide range of chemicals, including acids, bases, solvents, and hydrocarbons.
• Both materials can withstand high temperatures.
• FKM and FFKM offer good strength and elasticity.

Difference Between FKM and FFKM

Definition 

• FKM is a type of rubber that resists heat, chemicals, and oils, often used in seals and gaskets. FFKM is a stronger version of FKM that handles extreme temperatures and harsh chemicals.

Content

• FKM contains a high amount of fluorine atoms but also includes hydrogen atoms in its molecular structure. FFKM, on the other hand, contains a much higher proportion of fluorine atoms, with no hydrogen content.

Temperature

• FKM can withstand temperatures up to approximately 205°C (400°F), while FFKM offers a higher temperature rating, typically up to 325°C (617°F).

Chemical Resistance

• FFKM is more chemically resistant than FKM.

Compression Set Resistance 

• FKM shows better compression set resistance compared to FFKM. 

Conclusion 

Both FKM and FFKM are polymeric materials. The main difference between FKM and FFKM is that FFKM has a higher fluorine content than FKM. They are used in a wide range of applications due to their chemical and temperature resistant properties.

FAQ: FKM and FFKM

1. What does FFKM stand for?

FFKM stands for fluorinated fluoroelastomer. It’s a type of rubber with exceptional resistance to high temperatures and chemicals.

2. What is the difference between FFKM and FFPM?

FFKM and FFPM are both fluorocarbon polymers, but FFKM has a higher fluorine content than FKM.

3. Is FFKM the same as PTFE?

FFKM and PTFE are both fluorocarbon polymers, but they have different properties. FFKM is an elastomer, while PTFE is a thermoplastic. 

4. What is the temperature limit for FFKM?

FFKM can withstand temperatures from -20°C to 325°C, which makes it suitable for high-temperature applications.

5. What are the applications of FFKM?

FFKM is ideal for applications like O-rings, seals, and gaskets in industries such as aerospace, chemical processing, and oil and gas.

Reference:

1. “FKM.” Wikipedia. Wikipedia Foundation.

2. “FFKM.” Wikipedia. Wikipedia Foundation.

Image Courtesy: 

1. “FFKM FFPM CKD900 plate 80mm 80mm 1mm.” By Johannes Schneider (CC BY 4.0) via Commons Wikimedia