Synthesis and characterization of PEE-PEO diblock copolymers with complementary end-groups for hydrogen-bond heteroassociation

Poly(ethylethylene-b-ethylene oxide) (PEE-PEO) diblock copolymers with pyridine-benzoic acid end-groups for heterodimeric hydrogen bonding were designed as a possible means to noncentrosymmetric organizations by spontaneous self-assembly. These end-functionalized polymers were synthesized by anionic living polymerization with protected initiator and terminating reagents. A series of polymeric intermediates with different end-groups was characterized by proton nuclear magnetic resonance, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and gel permeation chromatography. Preliminary studies of solid-state organization by differential scanning calorimetry and small-angle X-ray scattering provided evidence for a long-range order that was sensitive to chain length, copolymer composition, and end-group structure.