Synthesis, Characterization, and Aggregation Behavior of Block Copolymers Bearing Blocks of Lipid−Mimetic Aliphatic Double Chain Units

A number of diblock and triblock copolymers of ethylene oxide and 1,3-didodecyloxy-2-glycidyl-glycerol (DDGG), an epoxide monomer bearing a lipid−mimetic anchor, were synthesized via anionic polymerization. The copolymers were characterized by 1 H nuclear magnetic resonance spectroscopy and gel permeation chromatography. Their self-association in aqueous environment was studied by simultaneous static and dynamic light scattering, and the particles were visualized by means of cryogenic transmission electron microscopy. The weight-average molecular weights, the radii of gyration, the second virial coefficients, the diffusion coefficients, and the hydrodynamic radii of the particles were determined. The particles were of nanodimensions with weight-average molecular weights up to tens of millions and consisted of hydrophobic poly(DDGG) and hydrophilic PEG chains in the core and corona, respectively. The results indicate formation of PEG−water domains randomly distributed in the cores. Dynamic light scattering of selected copolymers carried out in extended temperature and concentration intervals revealed a formation of dense particles. The density of the particles was found to increase with a temperature increase.