Two Pathways of Thiolactone Incorporation into Polyurethanes and Their One-Pot Double Postfunctionalization

Abstract

Thiolactone-functionalized polyurethanes were produced by using a chain extension method. Isocyanate−telechelic urethane prepolymers of different chain lengths were prepared from two different diols and 4,4′-methylenebis(cyclohexyl isocyanate), and then reacted with two different thiolactone-functionalized diols, yielding polyurethanes bearing thiolactone groups either within or along the polymer backbone. Postmodification reactions were performed according to an amine−thiol− thiosulfonate conjugation strategy using various functional amines and thiosulfonates. Different characterization techniques were implemented to prove the double modification, for example, 1 H NMR, 19 F NMR, SEC, DSC, and fluorometry.

Synthesis and research of basalt microfiber‐reinforced polyurethane elastomer composites

“…Polyurethane elastomers (PUE) are a kind of versatile polymers 1–3 . It contains soft segments composed of polyols and hard segments composed of isocyanates and chain extenders, which have microphase separation in terms of microstructure 4–6 .…”

Thiolactone chemistry, a versatile platform for macromolecular engineering

“…Thiolactone double modification using amine/thiol-disulfide interchange reactions. The thiol groups released from the thiolactone rings during the aminolysis reactions were also reacted with different scavengers, such as thiosulfonates, 97,100 or pyridyl-disulfide compounds 92 in order to generate disulfide bonds by thiol-disulfide interchange reactions. Unlike Michael acceptors, these scavengers do not react with amine groups, reducing the need of reactant excess.…”

“…10 One-pot double post-polymerization modification reactions of thiolactone-containing polyurethanes. 97…”

“…5.9 and 5.10) were reacted with isocyanate–telechelic urethane prepolymers of different chain lengths, resulting in polyurethanes bearing thiolactone groups either within or along the polymer backbone and with different densities of functionalization. 97…”

“…10). 97 If both localization could be modified, in-chain thiolactones were less reactive than side-chain thiolactones due to higher steric hindrance.…”