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Amphiphilic gradient and block copolymers represent an interesting class of materials due to their ability to self-assemble into different structures. The combination of hydrophobic polysiloxanes with hydrophilic polyethers results in amphiphilic structures that are promising due to their chemical stability and biocompatibility. These characteristics enable a wide range of surfactant applications in various industrial sectors e.g. for pharmaceutical purposes. Copolymerization of cyclic siloxanes with epoxides is a challenging task which we can encounter by usage of the double metal cyanide (DMC) catalyst. The implementation of different synthesis conditions allows controlled copolymerization of cyclosiloxanes and epoxides both to statistical as well as block copolymers that are inaccessible by other methods like common anionic polymerization techniques. |
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The combination of hydrophobic polydimethylsiloxane (PDMS) blocks with hydrophilic polyether segments plays a key role for silicone surfactants. Capitalizing on the double metal cyanide (DMC) catalyst, the direct (i.e., statistical) copolymerization of cyclic siloxanes and epoxides is shown to be feasible. The solvent‐free one‐pot copolymerization of hexamethylcyclotrisiloxane and propylene oxide results in the formation of gradient propylene oxide (PPO)‐PDMS copolymers. The polymerization kinetics are investigated by pressure monitoring and in situ 1H and in situ 29Si NMR spectroscopy. This unusual copolymerization offers promise for the synthesis of silicone/polyether polyols. |
