Facile synthesis and self-assembly of amphiphilic polydimethylsiloxane with poly(ethylene glycol) moieties via thiol-ene click reaction

We demonstrate here a facile and efficient synthesis of polysiloxane-based amphiphilic copolymers via thiol-ene click chemistry. The properties of PEG-b-PDMS-b-PEG (T-PPG) and PDMS-g-PEG (S-PPG20 and S-PPG100) amphiphilic copolymers were studied in detail by a combination of 1H NMR, FT-IR, gel permeation chromatography, and thermogravimetric analysis. In comparison with the traditional hydrosilylation method which requires the noble metal catalyst platinum, the newly designed thiol-ene protocol produces polysiloxane-based amphiphilic copolymers with only anti-Markovnikov addition products under benign conditions. The resulting copolymers have lower critical aggregation concentration (CAC), and dynamic light scattering (DLS) results revealed that the obtained amphiphilic copolymers can self-assemble into nanoparticles (128 nm to 198 nm) in aqueous solutions with a narrow size distribution (PDI is less than 0.24).