PTFE-Naphthalene Solution Treatment Bonding Method

The sodium naphthalene solution treats fluorine-containing materials, mainly through the chemical reaction between the corrosive liquid and the PTFE plastic, to tear off part of the fluorine atoms on the surface of the material, so that a carbonized layer and some polar groups are left on the surface. Infrared spectroscopy shows that polar groups such as hydroxyl, carbonyl and unsaturated bonds are introduced into the surface, which can increase the surface energy, reduce the contact angle, improve the wettability, and change from difficult to sticky to sticky. This is the most effective method among all the methods currently studied, and it is also the most commonly used method. Generally, sodium naphthalene tetrahydrofuran is used as the etching solution.

The processing and bonding steps of PTFE are as follows:

(1). Preparation of treatment solution: add a certain amount of sodium metal to the solution of tetrahydrofuran and naphthalene, wherein the mass fraction of sodium metal is controlled at 3% to 5%, and stir at room temperature for about 2 hours until the color of the solution is dark brown. or black;

(2). Immerse the PTFE workpiece to be treated in the solution for about 5~10min, take it out and soak it in acetone solution for 3~5min;

(3). Take out the workpiece from the acetone solution, rinse it with clean water, and place it in a dark place to dry naturally;

(4). Choose epoxy resin, silicone or polyurethane as the adhesive, evenly apply it to the treated surface to be bonded and bond immediately. After standing at 24~30°C for 24 hours, the bond will be firm.