News Coatings Technologies
Thiol–yne route delivers perfectly alternating hybrid copolymers
Researchers have synthesised perfectly alternating linear-dendritic copolymers using dithiol–yne click chemistry. The approach combines bis-MPA dendrons with linear dithiol spacers, offering precise control over polymer architecture and opening new possibilities for tailored hybrid macromolecules.
Hybrid linear-dendritic polymers are of growing interest because they combine the precise branching of dendrons with the flexibility of linear segments. In this study, a perfectly alternating linear-dendritic (ALD) copolymer was prepared via thiol–yne click chemistry. The architecture relies on a dendritic macromonomer based on 2,2′-bis(hydroxymethyl)propionic acid (bis-MPA) bearing an alkyne focal point (A2), which reacts with a dithiol linker (B2) in a step-growth polymerisation.
To identify optimal reaction conditions, the researchers varied the dendron generation (G1–G4) and the alkyl chain length of the dithiol linker, aiming for the highest increase in number-average molecular weight (Mn) while maintaining a dispersity below 2.0.
“Reading tip: Functional Coatings
The EC Tech Report “”Functional Coatings“” gives you an up-to-date bundle on functional coatings with articles, videos and other handpicked content. In addition to technical articles about the latest technical developments, this all-in-one multi-media pack is rounded off with valuable market insights and important fundamentals about functional coatings formulation.”
Size exclusion chromatography (SEC) revealed that polymerisation of propargyl[G4]Ac with alkyl dithiols mainly produced oligomers such as dimers and trimers. In contrast, propargyl[G1]Ac monomers yielded alternating copolymers with a higher number of repeat units, averaging around seven. The length of the dithiol linker also affected the kinetics: 1,4-butanedithiol led to copolymers with fewer repeat units than 1,6-hexanedithiol or 1,10-decanedithiol under a 30-minute UV exposure.
Matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry confirmed the presence of both cyclic and linear structures. A library of hybrid ALD copolymers was synthesised and fully characterised by MALDI-TOF MS, SEC and nuclear magnetic resonance (NMR), providing a versatile toolbox for the design of next-generation hybrid macromolecular architectures.
Source: Miles, A. V. et al., Perfectly alternating linear-dendritic polymers via dithiol–yne click chemistry. Polymer Chemistry (2026).
