Highly functionalized, aliphatic polyamides via CuAAC and thiol-yne chemistries

The first step in the synthesis of functionalized polyamides consisted in the introduction of alkyne side groups in several types of linear polyamides by interfacial step-growth polymerization of hexane-1,6-diamine or 4,9-dioxadodecane-1,12-diamine in combination with on one hand adipoyl or sebacoyl chloride and on the other hand an alkyne-containing building block, i.e. 2-methyl-2-propargylmalonic acid dichloride. Both homo- and copolyamides were synthesized, creating a large range of alkyne-containing polyamides with degrees of functionalization ranging between 5% and 100%. Subsequently, these polyamide chains have been modified with two types of linking chemistries, respectively with azides through the copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition or with thiols through the thiol-yne addition reaction.

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► Linear, aliphatic polyamides containing alkyne functional groups were prepared via step-growth polymerization.
► Homo- and copolyamides were synthesized without protection or deprotection steps.
► The polyamides were functionalized using the Cu(I)-catalyzed azide-alkyne cycloaddition and thiol-yne reaction.
► The thermal properties before and after functionalization were investigated.