Amphiphilic diblock copolymers based on sucrose methacrylate: RAFT polymerization and self-assembly

Diblock copolymers based on methyl methacrylate and sucrose methacrylate were synthesized by Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization and characterized by C-13 and H-1 nuclear magnetic resonance and size exclusion chromatography. The copolymers solutions were investigated in terms of solubility, swelling tests and dynamic light scattering in different solvents. Copolymers containing from 5 to 35 mol% of hydrophilic monomer present a typical solubility behavior of amphiphilic polymers and self-assemble capability in solution. While poly(sucrose methacrylate) is water soluble, copolymers self-assemble in water and the highest molar mass copolymers swell, achieving a maximum water swelling ratio of 250%. SEM images of the aggregates formed in water after freeze-drying reveal the presence of monomodal and spherical particles, some of them exhibiting a vesicular structure. The copolymers efficiently promote emulsification of aromatic solvents in water, enabling the transference and stabilization of the aromatic solvent and an aromatic dye in the aqueous phase, suggesting a possible application as delivery systems. Moreover, films of the copolymers prepared by casting from solutions in different solvents are also capable to self-assemble forming mainly lamellar structures, as verified by SAXS. The morphology of dispersed spheres of poly(sucrose methacrylate) throughout a poly(methyl methacrylate) matrix is also observed by AFM and TEM. (C) 2018 Elsevier B.V. All rights reserved. (AU)