One-Step Approach to Polyester-Polyether Block Copolymers Using Highly Tunable Bicomponent Catalyst

Phthalic anhydride and propylene/ethylene oxide are copolymerized at room temperature by a bicomponent metal-free catalyst comprising a mild phosphazene base and triethylborane. Provided with proper loadings of the two catalytic components, block copolymers with strict (AB)(n)B-m type sequence structures and controlled molar mass (up to 60 kg mol(-1)) can be generated in one synthetic step, and the block architecture can be enriched by the use of mono-, di-, or tetrahydroxy initiators. The obtained polyester-polyether block copolymers readily undergo microphase-separation in bulk and nanoaggregation in selective (aqueous and alcoholic) solvents.