Triblock Copolymers Based on Sucrose Methacrylate and Methyl Methacrylate: RAFT Polymerization and Self-Assembly

ABA and BAB triblock amphiphilic copolymers based on sucrose methacrylate and methyl methacrylate are synthesized by sequential reversible addition-fragmentation chain transfer polymerization using S,S '-bis(R,R '-dimethyl-R ''-acetic acid)-trithiocarbonate as a chain transfer agent. The copolymers present narrow molar mass dispersity, controlled molar mass and architecture as determined by gel permeation chromatography and H-1 and C-13 nuclear magnetic resonance. The copolymers with molar and mass fractions of poly(sucrose methacrylate) block ranging from 1 to 22 mol% and 3 to 52 wt%, respectively, and different molar masses present characteristics of a surfactant such as self-assembly. The self-assembly of the triblock copolymers in water, N,N-dimethylformamide (DMF), dichloromethane, tetrahydrofuran, or benzene results mostly in vesicles as confirmed by scanning electron microscopy images and small-angle X-ray of the dispersions. Moreover, the copolymers present the capability to stabilize aromatic molecules (Nile Red dye) and nonpolar solvents in an aqueous phase and polar ionic molecules (methylene blue) and water in a nonpolar medium, suggesting the potential for application in drug encapsulation, environmental remediation systems, and molecular extraction in liquid-liquid immiscible systems, for example. Films prepared by casting from copolymer solutions in DMF present a lamellar structure with the lamellar thickness varying according to the copolymer molar mass.