Silicones / Si-based Polymers

1. Development of Novel Siloxane-Based Polymers

Polysiloxanes are characterized by a number of unique features that divide them from all kinds of other known macromolecules. The extraordinary properties of their Si-O backbone provide them an exceptional position within plastics industry. It results in an extremely high chain flexibility, giving them by far the lowest glass transition temperature of all polymers and a gas permeability that is equally outstanding. Besides this, due to the fact that living organisms are absolutely inert towards the non biological siloxane structures, silicones are highly applicable in the medical field. In order to further increase the spectrum of silicone applications, we developed a facile route to create hydrophilic silicones by grafting polysiloxanes with glycerol or oligoglycerol sidechains via hydrosilylation chemistry. It could be shown that hydrophilicity and glass transition temperature of the resulting silicones can be tuned over a broad range simply by varying the character and amount of sidegroups.


Figure 1: Synthesis Properties of Hydrophilic Polysiloxanes

2. Multihydroxy-functional Polysilanes

A series of polar, multihydroxy-functional polysilanes has been synthesized via alkali-mediated Wurtz coupling of a novel acetal-protected silane monomer (DCIMS) and dichlorodihexylsilane (DCDHS). Subsequent deprotection yields random copolymers (P(DHS-co-GMS)) with the multiple hydroxyl moieties providing intriguing possibilities for further functionalization sequences and the synthesis of complex macromolecular architectures.


Figure 2: Synthesis of multihydroxy-functional polysilanes

References

[1] "Multihydroxy-Functional Polysilanes via an Acetal Protecting Group Strategy" V. S. Reuss, H. Frey, Macromolecules 2010, 43, 8462–8467. DOI: 10.1021/ma1016715.