Synthesis of well-defined rod-coil diblock copolymer of aromatic polyether and polyacrylonitrile by chain-growth condensation polymerization and atom transfer radical polymerization

The synthesis of diblock copolymers of aromatic polyether and polyacrylonitrile (PAN) was conducted by chain-growth condensation polymerization (CGCP) and atom transfer radical polymerization (ATRP) from an orthogonal initiator. When CGCP for aromatic polyether was carried out from a PAN macroinitiator obtained by ATRP with an orthogonal initiator, decomposition of the PAN backbone occurred. However, when ATRP of acrylonitrile was conducted from an aromatic polyether macroinitiator obtained by CGCP followed by introduction of an ATRP initiator unit, the polymerization proceeded in a well-controlled manner to yield aromatic polyether-block-polyacrylonitrile (polyether-b-PAN) with low polydispersity. This block copolymer self-assembled in N,N-dimethylformamide to form bundle-like or spherical aggregates, depending on the length of the PAN units in the block copolymer.