Synthesis of amphiphilic block copolymers of poly( ethylene oxide)and poly( methyl methacrylate)( PEO-b-PMMA) and their self-assembly in solution

Two kinds of amphiphilic block copolymers PEO-b-PMMA were synthesized by atom transfer radical polymerization using PEO-Br as the macroinitiator. Well defined copolymers PEO45-b-PMMA130 and PEO45-b-PMMA335 were characterized by GPC and1H-NMR. Self-assembly of PEO-b-PMMA in solution was investigated using dioxane as the initial common solvent. The critical water content and the aggregate morphology were characterized by light scattering and transmission electron microscopy. The results indicate that when the length of the PMMA block was increased,the critical water content decreased from 27. 5% to 22. 5%,and the average size of the spherical aggregates increased from 44 nm to 76 nm.