Green synthesis of sulfur-containing polymers by carbon disulfide-based spontaneous multicomponent polymerization

Abstract

Sulfur-containing polymers have gained much attention in polymer science due to their unique properties. However, their preparation has posed considerable challenges, particularly in diversifying their structures and achieving highly efficient polymerizations. This is especially true for polymers derived from CS₂, a readily available one-carbon (C1) feedstock, as their synthesis often requires the use of harsh conditions or results in unexpected by-products. In this work, we established a regio-selective and atom-economical spontaneous multicomponent polymerization based on carbonyl or ester group-activated internal alkynes, commercially available amines, and CS₂. Similar to the angled half lap joint of two plates in a scarf joint of ancient Chinese “mortise and tenon” architecture, internal ethynyl and amino groups cannot be readily linked at room temperature, whereas added CS₂ acts as a “wedge” to make the monomers spontaneously expand into tight linkages of polymer chains with satisfactory molecular weights (up to 31 600) in high yields (up to 97%). The polymers exhibited exceptional optical characteristics (refractive indices of up to 1.7471 at 632.8 nm) and good film-forming capabilities. This polymerization opens up a new avenue for the green and efficient synthesis of functional sulfur-containing polymers with low energy consumption, minimized waste generation and efficient use of CS₂ resources.