Precision Synthesis of Degradable Alternating Copolymers of Fluorine-Containing Vinyl Ethers and Conjugated Aldehydes

Abstract

Degradable alternating copolymers with distinctly fluorous characteristics were synthesized via controlled cationic copolymerization of perfluoroalkyl vinyl ethers (VEs) and conjugated aldehydes. Well-defined alternating copolymers were obtained using the EtSO₃H/GaCl₃ initiating system in the presence of 1,4-dioxane as an added base and 2,6-di-tert-butylpyridine as a proton trap in a fluorine solvent at −78°C. Various conjugated aldehydes and fluorine-containing VEs were also investigated for controlled alternating cationic copolymerization. The solubility of the obtained alternating copolymers improved compared to the fluorine-containing VE homopolymer. In particular, copolymers underwent upper critical solution temperature-type phase separation behavior in various solvents. In addition, polymer thin films of the alternating copolymers exhibited high water and oil repellency. All alternating copolymers were decomposed into small molecules under an acidic condition without residual oligomers in both solution and thin film state.