Synthesis of Fluorinated Polyurethane Acrylate and Its Application in Gas Separation Membranes With Improved Antioxidant Properties

Abstract

Conventional gas separation membranes are mostly aimed at improving the permeability and selectivity of membranes. However, the actual application environment is complex and changeable, and the failure of the material is a common problem in the use process. Fluorinated polyurethane acrylate was synthesized via the fluorinated unit alcohol end-capping approach to enhance the antioxidant capacity of gas separation membranes. The fluorine element is used as an important part of the membrane structure, and then the antioxidant capacity of the membrane is enhanced. Specifically, hexamethylene diisocyanate isocyanurate (HDI) trimer and 1H, 1H, 2H, 2H-Tridecafluorooctanol (TFOA) were precisely metered and underwent an addition reaction. Subsequently, two molecules of the resulting addition products were connected to a molecule of 1,6-hexanediol (HDO). This was followed by a nucleophilic addition reaction between hydroxyethyl methacrylate and the fluorine-rich molecular formula, yielding fluorinated polyurethane acrylate (FPUA). To fabricate the gas separation membrane, photoinitiators were incorporated into the FPUA, followed by curing under UV irradiation. Under optimized conditions, the membrane exhibited exceptional performance in CO₂/SF₆ separation, achieving a gas selectivity of 126.11. The presence of abundant carbon, fluorine, and oxygen atoms in the separation layer significantly bolstered its antioxidant properties. After immersion in a 1 g/L NaClO solution for 7 days, the membrane exhibited minimal corrosion loss of only 1.5% ± 1.3%, and the water contact angle decreased by just 1.8°. This robust membrane material offers promise for the separation of mixed gases containing oxidizing components.