What is PCTFE – Everything You Need to Know About It | DCW

What is PCTFE – Everything You Need to Know About It

PCTFE, an acronym for Polytrifluorochloroethylene is among the earliest synthesized and commercialized fluoropolymers. Its discovery was made in 1934 by Fritz Schloffer and Otto Scherer who was a staff at IG Farben. But it was later commercialized by M.K Kellogg in the early 1950s under the trade name, Kel-F 81.

 

Due to its outstanding properties, it has remained in use over time despite the discovery of other fluoroplastics. Items made from PCTFE plastic have played important roles in some high-tech industries, such as the medical, chemical, aerospace, and electrical fields.


As a professional PCTFE manufacturer, in this post, we will be sharing with you everything you need to know about the PCTFE material, starting from what it is, its chemical structure, manufacturing process, properties, and applications.

What is PCTFE

Four PCTFE Valve Parts display
Source: Dechengwang

PCTFE is a thermoplastic chlorofluoropolymer with the molecular formula, (CF2CCIF)n, where:

n = the number of monomer units in the plastic molecule.

 

This chemical structure is made by the free-radical polymerization of chlorotrifluoroethylene (CTFE) and can be prepared by solution, suspension, bulk, and emulsion polymerization. 

 

With exceptional stiffness, strength, and dimensional stability, PCTFE is similar to Polytetrafluoroethylene (PTFE), except that it has a different chemical structure. Instead of Fluorine which is used in PTFE, Chlorine is introduced in PCTFE, leading to a massive change in the plastic’s properties and applications. Chlorine has a bigger atom, which breaks the structural regularity and leads to a decrease in the crystallinity of the plastic chains.

 

PCTFE’s reduced crystallinity and structural regularity result in a lower melting point and makes it available as a transparent product in films and thin sheets. Asides from this, the intermolecular forces also increase, making PCTFE a strong and hard plastic. And it has a wide range of temperatures, which makes it capable of withstanding harsh conditions, including cold flow and high thermal frequencies.

 

By altering the cooling process in the melting operation, the crystallinity of the PCTFE can be changed. This is done to make the polymer have more properties and be useful for a wide variety of applications. When the PCTFE has high crystals, it is dense with great mechanical properties and elongation. In contrast, PCTFE becomes lighter, clearer, and more elastic when quenched. And this is frequently used in cryogenic engineering applications for handling liquid oxygen and nitrogen.

How is PCTFE Manufacutred?

Workers operating on PCTFE manufacture machines
Source: Dechengwang

PCTFE is produced through conventional plastic manufacturing processes, such as injection molding, extrusion molding, and compression molding. But its production is not as simple as other polymers and this is because of the following reasons:

 

  • Zero-strength time (ZST): The manufacturing process leads to a reduction in ZST, which is a measure of molecular weight for PCTFE polymers. A higher ZST results in a PCTFE material with more properties, while a lower ZST is equivalent to lesser physical properties.
  • Crystallinity: PCTFE has a low crystallinity rate, which has a direct impact on PCTFE properties and is generally affected by ZST and the cooling rate during the melting operation.
  • Residual stress: This happens during the melt processing operation and it’s caused by the type of processing operation, exposure to shear, and cooling rate. A good way to reduce residual stress is to use compression molding. Another method is to subject the product to a high temperature, which will reduce the stress.

Properties of PCTFE

Two PCTFE Multi-way Valves in display
Source: Dechengwang

As earlier mentioned, PCTFE properties are enormous and unique from other polymers. They include:

  • High tensile strength with good thermal capabilities.
  • PCTFE temperature range is within -240⁰C (-400⁰F) to 150⁰C (302⁰F), making it non-flammable and highly functional in unconducive conditions.
  • A very low coefficient of thermal expansion with the glass transition temperature being around 45⁰C.
  • PCTFE plastic features one of the highest Limiting Oxygen Index (LOI) and zero tolerance to moisture absorption and wetting.
  • Excellent resistance to stress-crack and creep.
  • Reduced gas permeation and outgassing.
  • Thanks to the presence of high fluorine content, PCTFE is resistant to most chemicals and oxidizing agents.
  • The molecular asymmetry of PCTFE’s repeating unit allows it to exhibit a permanent dipole moment, which is perpendicular to the carbon-chain axis.
  • Since it contains fluorine, which has a less atomic radius, PCTFE doesn’t get close-packed. This results in a lower melting point (210⁰C to 215⁰C) among all fluoropolymers.
  • PCTFE polymer is highly resistant to radiation and doesn’t absorb visible light.

Applications of PCTFE

A PCTFE Multi-way Valve Connector
Source: Dechengwang

PCTFE is used across many industries for different purposes, which are highlighted below.

 

  • As a moisture barrier for food packaging, as well as pharmaceutical blister packaging.
  • For water-vapor barrier to safeguard phosphor coatings (they are susceptible to moisture) in electroluminescent lamps.
  • PCTFE’s high strength and electrical properties make it useful in making semiconductor components like water boats.
  • For the protection of liquid-crystal display panels that are sensitive to water.
  • Serving as a protective barrier against chemicals, PCTFE is used in chemical applications as a coating and prefabricated liner.
  • PCTFE material is used to laminate other plastic, such as PP, PVC, APET, PETG, etc.
  • Used in transparent eyeglasses, chemical tank liners, seals, O-rings, gaskets, valves, and tubes.
  • Thanks to its electrical resistance and water repulsion, it’s used to protect sensitive electronic components.
  • PCTFE serves as a protection for flexible printed circuits and insulation of cables and wires.
  • For the manufacturing of plates, clips, and foils as envelopes for cables and filaments.
  • It’s often used in the cryogenic and liquid gas sectors for making seals as it has low gas absorption and can withstand temperatures below 200⁰C.

Conclusion

PCTFE is widely recognized as one of the best polymers that can be used across several industries for multiple applications. It’s a unique plastic with outstanding properties, such as extreme strength, resistance to chemical, and water repulsion, which makes it highly functional in cases where other plastics falter.

 

Despite the increasing rise of PCTFE manufacturers on the market, Dechengwang has stood out as the most professional, experienced, and reliable company that’s capable of meeting all PCTFE material needs. Feel free to make a contact for the best services.

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