Controllable one-pot polycondensation of block polyaramid by temporary suppression of nucleophilicity

Abstract

Herein, we introduce controllable one-pot polycondensation which can prepare block aromatic polyamide by regulating nucleophilicity of amino groups through reversible coordination interaction. Due to different coordination ability of diamine monomers with Cu2+, effect of Cu2+ on its nucleophilicity is quite different and nucleophilicity is suppressed more significantly for the diamines with stronger coordination ability. Then, reactivity difference of diamine monomers owning different coordination ability can be magnified significantly through coordination interaction. When the two kinds of diamine monomers with different coordination ability exist in the reaction system, diamine monomer with weaker coordination ability reacts quickly with diacyl chloride in the initial phase of the reaction and forms corresponding chain segments. When the diamine monomer with weaker coordination ability is nearly depleted, the diamine monomer with stronger coordination ability begins to undergo uncoordinated reaction with Cu2+, restoring its reactivity with acyl chloride and forming corresponding chain segment in the second stage reaction.