Radical Coupling Allows a Fast and Tuned Synthesis of Densely Packed Polyrotaxanes Involving γ-Cyclodextrins and Polydimethylsiloxane
Résumé
The first radical end-coupling synthesis of polydimethylsiloxane (PDMS)-γ-cyclodextrins (γ-CDs) based polyrotaxane is reported. Conversely to usual chemical way, the radical process leads to fast both controlled size and structure with minimal side reaction while exhibiting very high conversion rate (w/w, 80%). Pure PDMS-γ-CDs molecular necklaces were successfully isolated by preparative size exclusion chromatography and finely characterized both by 1D/2D/STD 1H and 13C NMR and MALDI-TOF mass spectrometry. The observations give clear evidence of the supramolecular assembly synthesis where the filling ratio (γ-CD/monomer unit) of PDMS chains is as high as 40% of γ-CDs. Combination of such radical-based coupling supported by detailed analytical characterizations appears at the forefront of a fast, suitable, and easily amenable scaling-up CDs-based polyrotaxane synthesis process.
Mots clés
Chromatography
Cyclodextrins
Hydrogels
Mass spectrometry
Microchannels
Polydimethylsiloxane
Analytical characterization
Gamma-cyclodextrin
High conversions
Synthesis process
Silicones
Size exclusion chromatography
Supramolecular assemblies
Molecular necklace
Polydimethylsiloxane PDMS
MALDI-TOF mass spectrometry