Multicomponent click polymerization for the synthesis of coumarin containing 1,4-polytriazoles and their application as dye adsorbent

Abstract

The synthesis of heterocycle-based polymers have remained an important area of research in polymer chemistry. Herein we report a one-pot synthesis of a set of novel coumarin containing regioselective 1,4-polytriazols by multicomponent click polymerization using Cs2CO3 as a base and copper(I) acetate as a catalyst in DMF medium. In this one-pot process, O-alkylation followed by a three-component click reaction between the coumarin-linked dialkyne, sodium azide and alkyl/benzyl dibromides provide novel polymers having coumarin-triazole-linker (C-T-L) units. Ten novel polymers have been synthesized with high molecular weights (Mw = 20,080–46,340 g/mol) and very good yields (83–93%). All the polymers were well characterized by IR, NMR, and GPC. The dye removal capacities of these polymers were evaluated for methylene blue (MB), rhodamine B (RB), methyl orange (MO), and congo red (CR). Polymers P1, P2, and P3 showed very high affinity towards methylene blue dye and among them, P2 showed the highest dye removal efficiency (971 mg/g) for MB. The reusability of P2 was checked and found excellent removal efficiency (RE = 96%) up to the eighth cycle.