Synthesis, Hydrophilicity and Micellization of Coil-Brush Polystyrene-b-(polyglycidol-g-polyglycidol)...

In this paper, an original method of synthesis of Coil-Brush amphiphilic polystyrene-b-(polyglycidol-g-polyglycidol) (PS-b-(PGL-g-PGL)) block copolymers was developed. The hypothesis that their hydrophilicity and micellization can be controlled by polyglycidol blocks architecture was verified. The research enabled comparison of behavior in water of PS-b-PGL copolymers and block-brush copolymers PS-b-(PGL-g-PGL) with similar composition. The Coil-Brush copolymers were composed of PS-b-PGL linear core with average DP_n of polystyrene 29 and 13 of polyglycidol blocks. The DP_n of polyglycidol side blocks of coil-b-brush copolymers were 2, 7, and 11, respectively. The copolymers were characterized by ¹H and ¹³C NMR, GPC, and FTIR methods. The hydrophilicity of films from the linear and Coil-Brush copolymers was determined by water contact angle measurements in static conditions. The behavior of Coil-Brush copolymers in water and their critical micellization concentration (CMC) were determined by UV-VIS using 1,6-diphenylhexa-1,3,5-trien (DPH) as marker and by DLS. The CMC values for brush copolymers were much higher than for linear species with similar PGL content. The results of the copolymer film wettability and the copolymer self-assembly studies were related to fraction of hydrophilic polyglycidol. The CMC for both types of polymers increased exponentially with increasing content of polyglycidol.