What is the meaning of FFKM

High-performance elastomer FFKM (perfluoroelastomer) is renowned for its superior thermal stability, chemical resistance, and dependability in demanding industrial applications. This essay will examine the benefits, uses, and performance of FFKM and show why it is so well-liked in a variety of global businesses.

1Understanding FFKM

1.1 Definition and composition

A unique kind of perfluoroelastomer, or perfluorinated polymer rubber (Fluoroelastomer, FKM), is called FFKM. It’s an elastic synthetic material that can withstand high temperatures and strong chemical resistance. FFKM is made up of perfluorinated polymers, in which every hydrogen atom in the chain is swapped out for a fluorine atom.

The composition of FFKM mainly includes the following key components:

  1. Perfluorinated monomer: Trifluoroethylene, tetrafluoroethylene, and other fluorine-containing olefins are often polymerized to produce perfluorinated monomer, which is the primary ingredient in FFKM. The exceptional chemical stability and high thermal resistance of FFKM are attributed to these perfluorinated monomers.
  2. Cross-linking agent: Adding cross-linking agents is typically required to improve the mechanical and structural stability of FFKM. By creating a cross-linked structure between polymer chains, cross-linking agents improve the material’s resilience to compression and heat.
  3. Fillers and additives: Some fillers and additives are often added to FFKM in order to modify its physical features and processing attributes. Fillers have the ability to alter FFKM’s strength, hardness, and wear resistance. Carbon black, silica, and other common fillers are used. Antioxidants, plasticizers, and anti-aging agents are examples of additives that can enhance the anti-aging qualities and processing efficiency of FFKM.

2FFKM’s unique properties

2.1 Abnormal chemical resistance

  • Acidic media: concentrated sulfuric acid, concentrated nitric acid, concentrated hydrochloric acid, and many other strong acids are easily withstood by FFKM thanks to its exceptional resilience. Because of its resistance to corrosion and damage from acidic environments, FFKM is frequently used in chemical handling and storage equipment.
  • Alkaline media: FFKM has exceptional resistance to strong bases, including concentrated solutions of potassium hydroxide and sodium hydroxide. Because of this, FFKM is strong and dependable in chemical reactions involving alkaline media.
  • Organic solvents: Ketones, ethers, esters, aromatic hydrocarbons, and alkanes are just a few of the organic solvents that FFKM can withstand erosion of. Because of this, FFKM is the perfect material for applications requiring the handling and storage of solvents.
  • Oxidizing environment: Oxidizing agents including hydrogen peroxide, ozone, and oxygen are very resistant to FFKM. FFKM is resistant to oxidation, degradation, and aging and may retain both its sealing and physical qualities in an oxidizing environment.

2.2 High temperature stability

  • High temperature tolerance: In extremely hot or cold temperatures, FFKM can keep its chemical and physical characteristics. It is capable of withstanding temperatures as high as over 300°C and, in certain circumstances, as high as over 327°C. FFKM is perfect for applications needing strong sealing and corrosion resistance in high temperature settings because of its high temperature tolerance.
  • Excellent heat aging resistance is exhibited by FFKM, meaning that even after prolonged exposure to high temperatures, its chemical and physical characteristics do not change. Over time, its elasticity and dependability are maintained, with no discernible hardening, embrittling, or degradation.
  • Low volatility: At high temperatures, FFKM likewise shows minimal volatility. It is therefore appropriate for high-temperature applications needing minimal volatility, such as semiconductor production and sealing requirements in high-clean environments, since it does not leak hazardous compounds or create contamination.
  • Sustain sealing performance: FFKM can sustain strong sealing performance because of its resilience in high temperature settings. It is particularly well suited for sealing needs in high temperature and high pressure situations. It has exceptional elasticity and durability, and it can effectively resist leakage and contamination of media.
  • Thermal expansion coefficient matching: In high-temperature settings, the combination of FFKM and other materials becomes more stable since its coefficient of thermal expansion is similar to that of many metals and engineering plastics. This is crucial for high-temperature applications like chemical equipment and automobile engine parts that need for tight bonding with metals or other materials.

2.3 Excellent compression resilience

  1. High elasticity: FFKM can quickly regain its former shape after being crushed or distorted, indicating a high degree of elasticity. Because of its elasticity, FFKM can withstand cycles of compression loading and release while maintaining its sealing performance and shape stability.
  2. Low compression deformation: When compressed, FFKM exhibits remarkably little compression distortion. Without experiencing any appreciable permanent or plastic deformation, FFKM keeps its shape and dimensional stability even at high pressures.
  3. High resilience: After the compression stress is relieved, FFKM exhibits exceptional resilience, rapidly reverting to its initial size and form. Because of its exceptional robustness, FFKM is perfect for applications like piston rings, valves, and sealing components that need to be compressed and released often.
  4. Low compression set: FFKM resists compression sets quite well. FFKM can withstand extended pressure loading without experiencing appreciable permanent deformation, preserving its shape and dimensional integrity.
  5. Wide temperature range resilience: The compression resilience of FFKM is steady across a broad temperature range. FFKM is very dependable in a range of temperature applications because it can retain its exceptional resistance characteristics in both high and low temperature settings.

2.4 Low friction and wear resistance

  1. Low coefficient of friction: FFKM creates very minimal friction on the contact surface due to its incredibly low coefficient of friction. Because of its low friction nature, FFKM can increase equipment life and efficiency by lowering wear and energy waste in dynamic sealing and sliding applications.
  2. Wear Resistance: FFKM exhibits superior wear resistance, preserving the surface’s durability even in the face of intense pressure and friction. It can withstand wear, scratches, and surface damage because to its great hardness and scratch resistance.
  3. Anti-adhesion: Pollutants, lubricants, and solid particles find it difficult to stick to the surface of FFKM. Because of this, FFKM is anti-adhesive and self-cleaning in situations where contamination is high, lowering the need for frequent maintenance and cleaning.
  4. Matching: To lessen wear and friction, the surface of FFKM material may be properly matched with other materials (such as metal, plastic, etc.). It offers improved wear resistance and friction performance and is compatible with a variety of lubricants and lubrication systems.
  5. Temperature stability: Even in hot conditions, FFKM is able to hold onto its low friction and wear resistance qualities. It is resistant to wear and friction even in high-temperature environments, and the heat won’t cause it to lose its wear resistance or friction qualities.

2.5 Excellent mechanical properties

  • High tensile strength: FFKM can sustain significant forces under tensile loading because to its high tensile strength. Because of its overall strength advantage over other rubber materials, it performs dependably in applications requiring a high degree of strength.
  • Superior rip resistance: FFKM exhibits exceptional rip resistance, withstanding both ripping and rupture. This enables FFKM to withstand tensile or shear stresses without losing its integrity or durability.
  • Good oil resistance: FFKM can withstand contact with lubricants, solvents, and oil while maintaining its mechanical characteristics. It can function steadily in lubricant and liquid conditions for an extended period of time and won’t soften or expand when in touch with oil or other liquid media.
  • Elastic recovery: FFKM recovers from stress quite well, regaining its original shape in a short amount of time. Due to prolonged or recurrent stress, it can retain its elasticity and resilience and won’t undergo plastic deformation or irreversible deformation.
  • Low compression set: When compressed, FFKM shows a low compression set. FFKM resists considerable permanent or plastic deformation while maintaining shape and dimensional integrity, even under high pressure.

3Manufacturing and Composition of FFKM

3.1 Polymerization process

  1. Ionic polymerization: An ionic initiator is used to start the polymerization process. Benzophenone peroxide (BPO) or benzoyl peroxide (BPA) are the two most often utilized initiators in the ionic polymerization process of FFKM. At the right temperatures, these initiators break down to create free radicals, which start the polymerization of monomers such vinyl fluoride and fluorine-containing fluoromonomers. To produce high-quality FFKM materials, the ionic polymerization technique can regulate the polymerization reaction’s speed and molecular weight distribution.
  2. The process of polymerization triggered by a free radical initiator is known as free radical polymerization. Acetophenone peroxide (BPO) and dicumyl peroxide (BIPB) are two frequently utilized initiators in the free radical polymerization process of FFKM. When these initiators break down at the right temperature, free radicals are created that start the polymerization of monomers. Although the process of free radical polymerization is straightforward and inexpensive, it can be challenging to regulate the polymerization reaction, which might lead to the production of FFKM materials with a broad molecular weight dispersion.
  3. In order to maintain the polymerization reaction’s smooth progression and to regulate the reaction’s temperature and pressure, the reaction system often has to be supplemented with the proper solvents and stabilizers during the process. Typically, an inert environment is used throughout the polymerization reaction to prevent oxygen and other contaminants from influencing the process.
  4. Following the completion of the polymerization reaction, the resultant FFKM material must go through additional processing to give it the correct shape and size and to remove any remaining solvents, dispersants, and stabilizers. Processing techniques like thermoforming, extrusion, injection molding, etc., may fall under this category.
  5. In general, the polymerization process of FFKM mostly uses the free radical polymerization or ionic polymerization technique, with the initiator starting the monomer polymerization reaction. High-quality FFKM materials may be produced using these polymerization techniques for a range of high-performance uses.

3.2 Composition and structure

Perfluorinated monomer

  1. A range of perfluorinated monomers are often used in the polymerization of FFKM (perfluoroelastomer). Some frequently utilized FFKM perfluoromonomers are as follows:
  2. In FFKM polymerization, ethylene fluoride (CF2=CF2) is one of the most often utilized perfluoromonomers. It is an ethylene with strong chemical stability and high thermal resistance that contains fluorine.
  3. In FFKM polymerization, fluoropropylene (CF2=CFCF3) is another perfluoromonomer that is frequently utilized. It is more resistant to heat and chemicals because it has more fluorine atoms.
  4. Tetrafluoroethylene (C2F4): This perfluoromonomer is created when all four of the hydrogen atoms in an ethylene molecule are swapped out for fluorine atoms. Its electrical insulation, chemical resistance, and heat resistance are all quite good.
  5. Another popular perfluoromonomer is hexafluoropropylene (C3F6), which is made up of six fluorine atoms in place of each hydrogen atom in the propylene molecule. It resists chemicals and heat quite well.
  6. During the FFKM polymerization process, these perfluoromonomers polymerize into polymer chains, creating FFKM materials with exceptional qualities. The properties and functionality of FFKM materials may be tailored to match the demands of particular applications by changing the mix and ratio of perfluorinated monomers.
  7. Generally speaking, a range of perfluoromonomers, such as fluoroethylene, fluoropropylene, tetrafluoroethylene, and hexafluoropropylene, are used in the polymerization process of FFKM. Due to the high levels of chemical stability, heat resistance, and chemical resistance exhibited by these perfluorinated monomers, FFKM is a high-performance material that may be used in harsh environments.

Cross-linking agent

  1. The disulfide cross-linker is a frequently used fluorescent fluorescent metal cross-linker. Among them are dicumyl disulfide (DTB) and diphenyl disulfide (DPG). The double bonds in the FFKM polymer chain are vulcanized by these chemicals at high temperatures, creating a cross-linked structure that improves the material’s strength and wear resistance.
  2. Peroxide cross-linking agent: This substance is also frequently employed in the FFKM cross-linking procedure. Bithyrene peroxide (BPE-40) and di(4-tert-butylperoxy)butane (DBPH) are two common peroxide crosslinkers. Under heat activation, these cross-linking agents break down to produce free radicals, which start the cross-linking process in FFKM and result in the formation of a cross-linked structure.
  3. A molecule with two or more functional groups that can react with the active groups in the FFKM polymer chain to generate a cross-linked structure is known as a bifunctional cross-linking agent. Polyether glycol diacrylate (PEPA) and polyether glycol diacrylate (PEPE) are common bifunctional cross-linking agents.
  4. By creating a cross-linked structure between polymer chains, these cross-linking agents cause a cross-linking reaction in FFKM materials, enhancing the material’s strength, chemical resistance, and wear resistance. The required qualities and application might dictate the kind and quantity of cross-linking agent utilized.

3.3 Fillers and additives

Fillers:

  • One of the most often used fillers, carbon black may increase the FFKM’s strength, hardness, and wear resistance.
  • Nanoparticles can enhance the mechanical characteristics, wear resistance, and thermal stability of FFKM. Examples of these are nanosilica and nanoalumina.
  • Fibers made of cellulose, such as carbon, glass, etc., can improve the stiffness and strength of FFKM.
  • Graphite: Fillers made of graphite can increase FFKM’s wear resistance and thermal conductivity.

additive:

  • Plasticizer: Plasticizer helps make FFKM more flexible and processable.
  • Anti-aging agent: When used over an extended period of time, anti-aging agents can prolong the life of FFKM and stop material degradation and damage.
  • Accelerator: An accelerator can boost the cross-linking effect and quicken the FFKM cross-linking response.
  • Catalyst: A catalyst can hasten the FFKM polymerization process and encourage the synthesis of polymer.
  • Flame retardants: Flame retardants lower the chance of fire and increase the flame resistance of FFKM.

4Application fields of FFKM

  1. Chemical industry: FFKM is widely utilized in the chemical industry, including in pump components, pipelines, valves, and seals for chemical equipment. It can function steadily in a variety of acidic, solvent- and strongly alkaline situations for an extended period of time because to its resilience to corrosion and high temperatures.
  2. Oil and Gas Industry: The extraction, processing, and transportation of oil and gas all make extensive use of FFKM. It may be used to create parts that can endure high pressure, temperatures, and harsh media, such as rubber liners, pipe seals, O-rings, and corrosion-resistant seals.
  3. The food and pharmaceutical industries both use FFKM materials, which have several uses. It is employed in the production of valves, pipe connections, and seals to provide corrosion resistance and stringent hygienic standards.
  4. Semiconductor and electronics industry: FFKM is widely utilized in essential components such as O-rings, seals, and dust shields in the semiconductor and electronics industries because of its exceptional chemical resistance and low ion content.
  5. Aerospace sector: High-temperature and corrosion-resistant seals, O-rings, valves, and pipe connections are made using FFKM materials, which are crucial to this industry.
  6. Automotive Industry: FFKM is commonly utilized in the production of O-rings, pipe connections, sensors, and seals that are resistant to chemicals, oil, and high temperatures.
5 Conclusion

FFKM (perfluoroelastomer) is highly praised in the industry for its excellent performance and wide range of applications. Its excellent chemical resistance, high temperature stability and reliability make it an ideal choice in many critical applications. By taking full advantage of FFKM’s features, industries can improve equipment performance and reliability, resulting in higher production efficiency, reduced downtime, and greater economic benefits.