Stoichiometric Imbalance-promoted Step-growth Polymerization Based on Self-accelerating Three-component Reaction

A self-accelerating three-component reaction was developed using the secondary amines, CS2, and sym-dibenzo-1,5-cyclooctadiene-3,7-diyne (DIBOD) as reactants. In this three-component reaction, the secondary amine reacts with CS2 to form dithiocarbamate anion, which subsequently in-situ reacts with DIBOD behaving a self-accelerating reaction property. Specifically, the reaction of dithiocarbamate anion with the first alkyne of DIBOD activates the unreacted alkyne, which reacts with dithiocarbamate anion much faster than the original alkyne of DIBOD. Using the self-accelerating three-component reaction as polymerization reaction, a stoichiometric imbalance-promoted step-growth polymerization method was developed using the difunctional secondary amines, CS2, and DIBOD as monomer groups. This novel three-component polymerization can quickly produce high molecular weight dithiocarbamate-containing polymers under mild conditions using a slight molar excess of DIBOD to difunctional secondary amine monomer. Containing sulfur elements in the backbones, the resultant polymers hold high refractivity and may find potential applications in optical and optoelectronic fields.