Polysiloxane-backbone block copolymers in a one-pot synthesis: A silicone platform for facile functionalization

摘要

Block copolymers consisting exclusively of a silicon-oxygen backbone are synthesized by sequential anionic ring-opening polymerization of different cyclic siloxane monomers. After formation of a poly(dimethylsiloxane)(PDMS) block by butyllithium-initiated polymerization of D3, a functional second block is generated by subsequent addition of tetramethyl tetravinyl cyclotetrasiloxane(D4 ~V), resulting in diblock copolymers comprised a simple PDMS block and a functional poly(methylvinylsiloxane)(PMVS) block. Polymers of varying block length ratios were obtained and characterized. The vinyl groups of the second block can be easily modified with a variety of side chains using hydrosilylation chemistry to attach compounds with Si-H bond. Conversion of the hydrosilylation used for polymer modification was investigated. A new synthetic strategy for the two-step synthesis of block copolymers that exclusively consist of a silicon-oxygen backbone was developed. The applied two-step procedure involves anionic ring-opening polymerization and subsequent hydrosilylation to attach various functional molecules to one block of the polymer. Diffusion-ordered nuclear magnetic resonance spectroscopy was used to verify the structure of the obtained materials.