Multicomponent approach for the synthesis of functional copolymers via tandem polycondensations of isatoic anhydride, bisaldehydes and bisprimary amines in trifluoroethanol

Abstract

A novel multicomponent polymerization strategy based on the tandem reactions of isatoic anhydride with bisaldehyde and bisamine monomers under mild metal catalyst-free conditions was developed. • Multicomponent synthesis of poly(dihydroquinazolinone)s was achieved. • MCP utilizes isatoic anhydride, bisaldehyde and bisamine monomers. • Obtained polymers show pH-dependent phase changes. A novel multicomponent polymerization (MCP) strategy based on tandem reactions of isatoic anhydride with bisprimary amine and bisaldehyde monomers under mild metal catalyst-free conditions was developed, leading to tailor-made copolymers carrying dihydroquinazolinone groups in the main chains. Trifluoroethanol was employed as a solvent during polymerization due to its high solvating ability of growing chains as well as its strong Brønsted acid character that allows high activation of tandem polycondensations. Functional copolymers in the range from 8.5 kDa to 23.2 kDa molecular weights (M n ) were synthesized with moderately high monomer conversions. By simple alteration of bisaldehyde and bisamine monomers, a structurally diverse functional copolymer library was obtained. The polycondensation mechanism proceeds on the liberation of CO 2 and H 2 O byproducts and together with the solvent reusability, this multicomponent polymerization allows a green approach to functional polymer synthesis. The obtained results demonstrated that the corresponding cationic polymers display post-polymerization modification feature and pH-dependent phase changes that suggest their potential use in various material applications.