Hydrophilic modification method of polytetrafluoroethylene porous membrane

Abstract

The invention relates to a hydrophilic modification method of a polytetrafluoroethylene porous membrane. The method comprises the following steps: infiltrating the polytetrafluoroethylene porous membrane by using a fluorine-containing polyether polyol solution, polymerizing with polyisocyanate on the polytetrafluoroethylene porous membrane to generate a hydrophilic crosslinked-network polyurethane polymer in order to prepare a hydrophilic polytetrafluoroethylene porous membrane. The fluorine-containing polyether polyol is used to prepare polyurethane in order to process the polytetrafluoroethylene porous membrane in the invention, so the compatibility between polyurethane macromolecules and the polytetrafluoroethylene membrane is improved, and the hydrophilic processing effect is improved; the crosslinked-network polymer can be formed through solidification, so the hydrophilic effect endurance of the polytetrafluoroethylene porous membrane can be maintained; and the method is simple and easy to implement, and can maintain the acid resistance, the alkali resistance, the oxidation resistance and the heat resistance of the polytetrafluoroethylene membrane.

Description

technical field [0001] The invention relates to a hydrophilic modification method of a polytetrafluoroethylene microporous membrane. Background technique [0002] Polytetrafluoroethylene (PTFE) has good chemical stability, heat resistance, cold resistance and chemical corrosion resistance, excellent electrical insulation, small surface tension and friction coefficient, flame resistance, atmospheric aging resistance and high and low temperature adaptability Performance and other advantages, are widely used in chemical industry, electronics, medicine and cutting-edge technology fields. However, the surface tension of polytetrafluoroethylene microporous membrane is small and the non-polarity is strong, resulting in strong hydrophobicity and poor bonding performance of PTFE membrane, which can only be used in waterproof and breathable fields, which limits its application in sewage treatment, medical treatment, hygiene and other industrial applications. [0003] Researchers at ...

AI Technical Summary

Problems solved by technology

The wet chemical treatment method is mainly through the chemical reaction between the corrosive liquid and the surface of PTFE, destroying the C-F bond, tearing off some fluorine atoms on the surface, leaving a carbonized layer on the surface and introducing a certain polar group, thereby increasing the surface energy of PTFE , increased wettability, but this method also has some disadvantages, such as darkening or blackening of the surface of the adherend, lower surface resistance in high temperature environment, and long-term exposure to light will greatly reduce the bonding performance, etc.

The radiation grafting method is to irradiate the surface of PTFE with a radiation source, so that the functional monomers undergo chemical graft polymerization on the surface, so that a layer of graft polymer that is easy to bond is formed on the surface of the PTFE membrane. This method has a higher bonding strength. , the operation is simple and the processing time is short, but at the same time as the radiation modification, the properties of the material itself are also damaged, the surface durability is poor, and the Co 60 The radiation source is more harmful to the human body, so its application is also limited

Plasma treatment is to place the sample in a specific ion treatment device, through ion bombardment or implantation on the surface of the polymer, to cause C-C bond or C-F bond to break, and at the same time, functional groups can be introduced to activate the surface to achieve modification. The purpose of this method, but the device of this method is more complicated, the investment cost is high, and the failure of the vacuum system due to corrosion has not been fundamentally solved, and the improvement of the bonding strength after treatment is not ideal.