Surface Treatment of Polytetrafluoroethylene (PTFE)

As a professional source manufacturer of PTFE high-temperature fabrics, Jiangsu Aokai New Materials will introduce the surface treatment of polytetrafluoroethylene (PTFE).

PTFE features excellent high and low temperature resistance, outstanding chemical corrosion resistance, a low friction coefficient and self-lubricating properties. It is widely used in electronics, machinery, chemical equipment, aerospace, biomedicine and other fields, earning the reputation of the “King of Plastics”. However, due to its chemical inertness and low surface energy, PTFE is difficult to bond with other materials, which limits its applications to some extent. To improve the adhesion between PTFE and various materials, methods are usually adopted to enhance the surface activity of PTFE. For different products, Aokai New Materials generally applies the following PTFE surface modification methods.

1. Wet Chemical Treatment

The sodium-naphthalene chemical treatment is one of the effective methods for PTFE surface modification. With simple process and low cost, it is the preferred choice in practical production at Aokai New Materials’ PTFE factory.

Sodium-naphthalene treatment mainly uses an etching solution to react chemically with PTFE, removing some fluorine atoms from the surface. This leaves a carbonized layer and introduces polar groups such as hydroxyl groups, carbonyl groups and unsaturated bonds. These polar groups increase the surface energy of the polymer, reduce the contact angle and improve wettability, thus turning PTFE from non-bondable into bondable.

2. Mechanochemical Bonding Method

When polymers are subjected to external forces (e.g., crushing, grinding, friction, etc.), macromolecular chains break and undergo chemical reactions, including mechanodegradation, mechanochemical crosslinking, mechanochemical grafting, block copolymerization and stress-activated polymerization. These are known as polymer mechanochemical reactions.

In mechanochemical bonding, the adhesive-coated polymer surface is rubbed. Through mechanochemical action, the polymer surface undergoes mechanodegradation to form macromolecular free radicals, which then form covalent bonds with adhesive molecules, creating a strong bonding interface and greatly improving the bonding strength of the joint.

3. High-Temperature Melting Method

The basic principle of modifying PTFE surfaces via high-temperature melting is: at high temperatures, the crystalline morphology of the PTFE surface is altered, and high-surface-energy, easily bonded materials such as SiO₂ and Al powder are embedded. After cooling, a modified layer containing bondable substances forms on the PTFE surface. Since molecules of the bondable materials have penetrated into the surface molecular layer of PTFE, breaking the bond requires intermolecular destruction, resulting in high bonding strength.

4. Radiation Method

PTFE is placed in reactive polymerizable monomers such as styrene, fumaric acid, methacrylates and others, then irradiated with Co-60. This triggers chemical graft polymerization of the monomers onto the PTFE surface, forming a graft polymer layer that is easy to bond. Grafting also roughens the surface, increases the bonding area and enhances bonding strength.

5. Plasma Treatment Technology

Plasma treatment is one of the most rapidly developing technologies for PTFE surface modification in recent years.

The essence of this technology is to place the sample in a dedicated plasma treatment device, where ion bombardment or implantation breaks molecular bonds or introduces functional groups on the polymer surface, activating the surface to achieve modification. Ions can be inert gases, chemically active gases or metallic elements. Bombardment with inert gases can modify the surface structure of the polymer.

The above information is provided by Jiangsu Aokai New Materials Technology Co., Ltd.

For detailed parameters, application scenarios and customized solutions of our full product range — including PTFE high-temperature cloth, PTFE high-temperature tape, PTFE high-temperature mesh belt, seamless belts for bonding machines, single-sided PTFE cloth, high-temperature resistant conveyor belts, high-temperature resistant glass fiber cloth and more — please feel free to contact us:

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