O que é PTFE modificado?

Definition

 

Modified PTFE(also called Modified Teflon) is made by processing pure PTFE (Polytetrafluoroethylene) through special methods. It keeps the original advantages of PTFE while improving specific properties for better performance in certain uses.

 

Modification Methods

 

Filler Modification

 

This method mixes PTFE with different fillers to improve certain properties. Fillers can be used alone or combined, depending on the performance needed. Here are some common fillers and their functions:

 

Inorganic Fillers

Glass Fiber: Improves wear resistance, creep resistance, and stiffness

Carbon Fiber: Increases strength, heat transfer, and wear resistance

Graphite: Boosts wear resistance and lubrication

Molybdenum Disulfide: Enhances lubrication

 

Metal Fillers

Copper Powder: Improves heat transfer and wear resistance

Nickel Powder: Increases corrosion resistance and strength

 

Polymer Fillers

Polyimide: Improves creep resistance and high-temp stability

Polystyrene (PEEK, etc.): Increases wear resistance and stiffness

 

 

Chemical Treatment

 

This method changes the molecular structure of PTFE through chemical reactions. The most common is grafting modification, where monomers like styrene are grafted onto PTFE using gamma rays or electron beams. This boosts surface activity and bonding ability.

 

 

Surface Modification

 

Plasma Treatment: Uses plasma to add active groups to the surface. This improves wetting and bonding.

Laser Etching: Uses ultra-fast lasers to create tiny grooves. Often used for biosensors.

 

Background

 

PTFE is known for its excellent resistance to chemicals, low friction, and high temperature tolerance. But it also has weaknesses, like low strength and poor creep resistance. Modified PTFE solves these issues through targeted improvements.

 

Propriedades

Performance Comparison

Propriedade	Pure PTFE	PTFE modificado
Densidade	2.1–2.3 g/cm³	2.5–3.0 g/cm³
Resistência à tracção	15–30 MPa	20–50 MPa
Alongamento na ruptura	200%–500%	5%–300%
Hardness (Shore D)	50–65	60–85
Rigidez Dielétrica	15–25 kV/mm	5–20 kV/mm

Propriedades Químicas

Propriedade	Pure PTFE	PTFE modificado
Resistência à fluência	50%–100%	5%–30%
Permeability	1×10⁻¹⁰ cm³·cm/(cm²·s·Pa)	1×10⁻⁴ cm³·cm/(cm²·s·Pa
Estabilidade térmica	-200°C to 260°C	-200°C to 200°C

 

Choosing the Right Modification

 

Sealing Materials: Use 25% glass fiber + 5% graphite. Reduces friction by 40%. Ideal for high-pressure valves.

Medical Catheters: Plasma-grafted with acrylic acid. Increases surface hydrophilicity, reduces protein sticking by 60%.

High-Frequency Circuit Boards: Modified with nano-Aluminum Oxide. Keeps dielectric constant stable at 2.1–2.3 (at 1 MHz), suitable for 5G.

 

Price

 

Prices vary widely depending on the type and application. Generally, it ranges from 99 to 280 RMB per kilogram.