Functionalization of polyurethanes by incorporation of alkyne side-groups to oligodiols and subsequent thiol–yne post-modification

Abstract

A versatile and upscalable method for the synthesis of polyurethanes (PUs) bearing pendant functionalities at the hard-soft segment interface from easily accessible commercial oligodiols is described. Reactive alkyne groups were introduced to polytetrahydrofuran (PTHF), poly( -caprolactone) (PCL) and polydimethylsiloxane (PDMS) diols by cationic ring-opening polymerization of glycidyl propargyl ether using these oligodiols as macroinitiators. The resulting oligodiols, with alkyne side groups located at both chain ends, were subsequently reacted with 1,4-butanediol and hexamethylene diisocyanate for the synthesis of PUs, containing several pendant alkyne groups between the soft and hard segments. The functionalized PUs based on different soft segments (PTHF, PCL or PDMS) have been further modified via metal-free thiol-yne chemistry. Proper reaction conditions were found for quantitative radical thiol-yne coupling reactions with benzyl mercaptan and thioglycerol.

Study of Diels–Alder reactions between furan and maleimide model compounds and the preparation of a healable thermo‐reversible polyurethane

“…The synthesis of PU from 2,5‐bis‐(hydroxymethyl)furan was performed according to a previously reported procedure . In a two‐neck round‐bottom flask, 2,5‐bis‐(hydroxymethyl)furan (1 equiv.)…”

Protected thiol strategies in macromolecular design

“…Besides thiol-ene reactions, other radical and nucleophilic reactions are worth mentioning in the context of efficient thiol reactions. Radical thiol-yne additions allow for a double thiol addition, the second addition proceeding faster than the first [19,[34][35][36][37]. Nucleophilic reactions include the addition or nucleophilic substitution of a thiol to an oxirane, an isocyanate or an alkyl halide (e.g.…”

Carboxylic Acid Ionic Modification of Castor‐Oil‐Based Polyurethanes Bearing Amine Groups: Chemically Tunable Physical Properties and Recyclability

“…PUs can be functionalized by introducing functional groups into oligodiols and further polymerization, postpolymerization modification, or by combination of both strategies. Although the first approach is more experimentally feasible because it is straightforward to incorporate functional groups into low or medium molecular weight oligodiol, in practice PUs are functionalized by a variety of methods including the synthesis of polyols with reactive pendant groups to prepare novel comb‐type, grafted structural functional polymers through postmodification . So far, a few reports have focused on the preparation of novel functional bio‐based PUs with reactive pendant groups.…”