Fast and scalable production of hyperbranched polythioether-ynes by a combination of thiol-halogen click-like coupling and thiol-yne click polymerization

Abstract

Fast and scalable production of hyperbranched polythioether-ynes was achieved by applying sequential click chemistry (SCC) via couple-monomer methodology (CMM). As a typical example, thiol-halogen click-like reaction employing strong base, KOH and thiol-yne click reaction via UV irradiation were used for precursor preparation and polymerization, respectively. Two series of hyperbranched polythioether-ynes employing two kinds of di-thiols with different reactivity have been prepared within 10 h and characterized with ¹H NMR spectroscopy and gel permeation chromatography. The hyperbranched polymers (HPs) derived from 1,6-hexanedithiol reached high weight-average molecular weight (M_w) of 230500, high weight-average degree of polymerization (DP_w) of 1224 and high degree of branching (DB) of 0.82–0.68. Postmodification of abundant alkyne terminal groups afford HPs with a greatly enhanced DB of 0.96. Heat-initiated polymerization was also attempted. The present study clearly demonstrates the robustness of application of SCC technique in the CMM strategy for fast, scalable preparation of multifunctional HPs.