Surface modification method for polytetrafluoroethylene product

Abstract

The invention discloses a surface modification method for a polytetrafluoroethylene product. The method comprises the following steps of: coating polyethylene glycol on the surface of the polytetrafluoroethylene product, and then performing surface modification on the polytetrafluoroethylene product coated with the polyethylene glycol by adopting a plasma treatment method. Compared with the prior art, the polyethylene glycol element is introduced on the surface of the polytetrafluoroethylene product so as to effectively improve the surface activity of the polytetrafluoroethylene product, reduce the contact angle, improve the surface energy, remarkably improve the wetting property and the adhesion property of the polytetrafluoroethylene product and keep the polytetrafluoroethylene product for long time; and in addition, the method has little influence on the chemical property of the polytetrafluoroethylene product, has the advantages of convenient for operation, simple process, high processing speed, good treatment effect, low cost, energy conservation and emission reduction, is not easy to cause environmental pollution, and is more suitable for industrialized production.

Description

Technical field

[0001] The invention relates to the technical field of polymer material modification, in particular to a method for surface modification of polytetrafluoroethylene products. Background technique

[0002] Polytetrafluoroethylene (PTFE) is a polymer of tetrafluoroethylene, its structure is (-CF 2 -CF 2 -). CF in PTFE molecule 2 The units are arranged in a zigzag shape. Since the radius of the fluorine atom is slightly larger than that of hydrogen, the adjacent CF 2 The unit cannot be completely cross-oriented in trans, but forms a helical twisted chain with fluorine atoms covering almost the entire surface of the polymer chain. This fluorine atom shell protects the easily eroded carbon atom chain, so that the PTFE resin material has unique properties, that is, high chemical stability, electrical insulation, high and low temperature adaptability, self-lubrication, atmospheric aging resistance, Very low friction coefficient, non-combustibility and high mechanical str...

Examples

Embodiment 1

[0025] The PTFE oil seal sheet to be treated is immersed in polyethylene glycol with a molecular weight of 400, soaked at room temperature for 3 hours, and then taken out, and then put into a plasma generator, and plasma surface modification is performed in the plasma atmosphere. The treatment power is 200W, the treatment time is 15 minutes, and then washed with deionized water to remove polyethylene glycol that is not grafted on PTFE, and dried to obtain a surface-modified PTFE sealing sheet. The measured contact angle of the surface-modified PTFE oil seal is 56°, such as figure 2 Shown.

Embodiment 2

[0027] The PTFE oil seal sheet to be processed is immersed in polyethylene glycol with a molecular weight of 2000, soaked at 80°C for 5 hours and then taken out, and then put into the plasma generator, and plasma surface is performed in the plasma atmosphere area Modification, the treatment power is 300W, the treatment time is 20 minutes, and then washed with water to remove polyethylene glycol not grafted on the polytetrafluoroethylene, and dried to obtain a surface-modified polytetrafluoroethylene oil seal sheet. The contact angle of the surface-modified polytetrafluoroethylene oil seal was 82°.

Embodiment 3

[0029] The polytetrafluoroethylene oil seal sheet to be treated is immersed in an aqueous solution of polyethylene glycol, wherein the molecular weight of polyethylene glycol is 8000, and the concentration of polyethylene glycol is 80%; after soaking at room temperature for 4 hours, take it out and dry at 80°C. The solvent is dry removed, and then it is introduced into the plasma atmosphere area for plasma surface modification. The treatment power is 150W, the treatment time is 30 minutes, and then washed with water to remove polyethylene glycol not grafted on the polytetrafluoroethylene, and dried to obtain a surface-modified polytetrafluoroethylene oil seal sheet. The contact angle of the surface-modified polytetrafluoroethylene oil seal was 71°.

Technical field

[0001] The invention relates to the technical field of polymer material modification, in particular to a method for surface modification of polytetrafluoroethylene products. Background technique

[0002] Polytetrafluoroethylene (PTFE) is a polymer of tetrafluoroethylene, its structure is (-CF 2 -CF 2 -). CF in PTFE molecule 2 The units are arranged in a zigzag shape. Since the radius of the fluorine atom is slightly larger than that of hydrogen, the adjacent CF 2 The unit cannot be completely cross-oriented in trans, but forms a helical twisted chain with fluorine atoms covering almost the entire surface of the polymer chain. This fluorine atom shell protects the easily eroded carbon atom chain, so that the PTFE resin material has unique properties, that is, high chemical stability, electrical insulation, high and low temperature adaptability, self-lubrication, atmospheric aging resistance, Very low friction coefficient, non-combustibility and high mechanical str...

Examples

Embodiment 1

[0025] The PTFE oil seal sheet to be treated is immersed in polyethylene glycol with a molecular weight of 400, soaked at room temperature for 3 hours, and then taken out, and then put into a plasma generator, and plasma surface modification is performed in the plasma atmosphere. The treatment power is 200W, the treatment time is 15 minutes, and then washed with deionized water to remove polyethylene glycol that is not grafted on PTFE, and dried to obtain a surface-modified PTFE sealing sheet. The measured contact angle of the surface-modified PTFE oil seal is 56°, such as figure 2 Shown.

Embodiment 2

[0027] The PTFE oil seal sheet to be processed is immersed in polyethylene glycol with a molecular weight of 2000, soaked at 80°C for 5 hours and then taken out, and then put into the plasma generator, and plasma surface is performed in the plasma atmosphere area Modification, the treatment power is 300W, the treatment time is 20 minutes, and then washed with water to remove polyethylene glycol not grafted on the polytetrafluoroethylene, and dried to obtain a surface-modified polytetrafluoroethylene oil seal sheet. The contact angle of the surface-modified polytetrafluoroethylene oil seal was 82°.

Embodiment 3

[0029] The polytetrafluoroethylene oil seal sheet to be treated is immersed in an aqueous solution of polyethylene glycol, wherein the molecular weight of polyethylene glycol is 8000, and the concentration of polyethylene glycol is 80%; after soaking at room temperature for 4 hours, take it out and dry at 80°C. The solvent is dry removed, and then it is introduced into the plasma atmosphere area for plasma surface modification. The treatment power is 150W, the treatment time is 30 minutes, and then washed with water to remove polyethylene glycol not grafted on the polytetrafluoroethylene, and dried to obtain a surface-modified polytetrafluoroethylene oil seal sheet. The contact angle of the surface-modified polytetrafluoroethylene oil seal was 71°.

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