Hyperbranched Polymers by Thiol−Yne Chemistry: From Small Molecules to Functional Polymers

Abstract

A new synthesis of hyperbranched polymers is outlined. This paper presents the synthesis of hyperbranched polymers by the recently highlighted thiol-yne reaction. In the thiol-yne reaction, a catalytic amount of photoinitiator and UV radiation are used to add two thiols across one alkyne bond at room temperature. This work demonstrates how the thiol-yne reaction can be used to form hyperbranched polymers from both small organic molecules and polymeric chains bearing an alkyne and a thiol. The UV-catalyzed reaction is fast, forming high-molecular-weight polymers after 20 min of UV irradiation. Hyperbranched polymers made by the thiol-yne reaction have the potential to serve as new materials for a variety of applications from catalytic support and drug delivery to viscosity modification.

Hyperbranched Polymers with High Degrees of Branching and Low Dispersity Values: Pushing the Limits of Thiol–Yne Chemistry

“…Characterization data agrees with previously published synthetic method. 15 watt) in an aluminium foil lined dark box over a magnetic stirrer plate and feeding started at the same time as irradiation. The feeding was performed over a period of 20 min.…”

“…The monomer was polymerized under UV light (365 nm) with the radical photoinitiator 2,2-dimethoxy-2-phenylacetophenone (DMPA) in a 1.1 M solution in DMF, following a method similar to that previously published by our group. 15,17,18 A summary of the results is shown in Table 1. The reaction proceeds through the radicalmediated addition of a thiol to an alkyne followed by the addition of a second thiol to the formed vinylthioether to give a dendritic unit.…”

“…3 this enhanced reactivity are radical-mediated thiol-yne additions, which were re-introduced by the group of Bowman in 2009, 14 and applied in the synthesis of hyperbranched polymers with high degrees of branching by our group. [15][16][17][18] Another recent example involves coppercatalyzed azide-alkyne click chemistry, where the second B group reacts at a faster rate, due to the first triazole formed complexing the copper catalyst and causing faster reaction of the second moiety. 19 Accelerated strategies to dendrimer synthesis using orthogonal click chemistry have greatly improved applications of dendrimers and increased their availability to the scientific community, by reducing number of reaction steps and need for demanding purifications.…”

Thiol-yne click polymerization

“…In 2009, Perrier and coworkers [21] reported the synthesis of functional hyperbranched polymers by photo-initiated thiol-yne click polymerization under the assistance of the initiator of 2,2-dimethoxy-2-phenylacetophenone (DMPA). As shown in Figure 3, sulfur-containing hyperbranched polymers (hb-PI and hb-PII) were synthesized from prop-2-ynyl-3-mercaptopropanoate (PYMP) and a macromonomer of ATPST, respectively.…”

“…Indeed, the thiol-yne click reaction has been used to synthesize functional polymers with sulfurcontaining linear and topological structures [17][18][19][20][21][22][23][24][25][26][27][28], which have been widely applied in diverse areas [17,18,29]. While, to our best knowledge, there is no review to summarize its recent progress.…”