| Abstract [eng] |
The main goal of this work was to synthesize polyelectrolyte brushes containing poly(ethylene oxide) side chains by living polymerization. Brush-like macromolecules are unique polymer molecules whose conformation and physical properties are controlled by steric repulsion of densely grafted side chains. Molecules can be either flexible or stiff, depending on the grafting density and the length of the side chains. Polymerization of macromonomers is one of the most useful ways to prepare brush copolymers. However, with the macromonomer method, the distribution of the spacing of the side chains cannot be entirely controlled which along with broad and multimodal molecular weight distribution makes these polymers heterogeneous. These problems were considered to be overcome with the use of controlled/living polymerization. Conventional free-radical and RAFT copolymerization of poly(ethylene oxide) substituent containing methacrylate macromonomers, PEO5MEMA and PEO45MEMA, with methacrylic acid (MAA) was studied by the use of 1H NMR spectroscopy for an analysis of residual monomers. RAFT copolymerization of PEO45MEMA and MAA enabled to synthesize comb copolymers with low composition distribution and more homogeneous distribution of PEO side chains along the mainchain. Amphiphilic non-ionic blockcopolymers poly(lauryl methacrylate) (PLMA) – P(PEOnMEMA) and amphiphilic anionic blockcopolymers PLMA – PMAA were prepared by the RAFT method, and their properties in aqueous and THF solutions were studied. Cationic brush-on-brush polyelectrolytes with high density of PEO chains were prepared for the first time by ATRP method. Adsorption of novel cationic brush-on-brush polyelectrolytes on negatively charged silica surfaces was studied. The novel brush-on-brush polyelectrolytes are promising candidates for applications requiring good colloidal stability and they also are promising as lubricants in aqueous solutions. |
