Synthesis and Solution Properties of a Rigid Helical Star Polymer: Three-Arm Star Poly(quinoxaline-2,3-diyl)

摘要

Six semiflexible helical three-arm star poly[5,8-dimethyl-6,7-bis(propoxymethyl)quinoxaline-2,3-diyl] (A3PQ) samples which have different arm lengths ranging in the weight-average molar mass M-W from 1.5 x 10(4) to 2.5 x 10(5) g mol(-1) were synthesized via the living polymerization of the corresponding 1,2-diisocyanobenzene using a trifunctional palladium initiator. The particle scattering function P(q), the z-average mean-square radius of gyration < S-2 >(z), and the intrinsic viscosity [eta] for the A3PQ samples were determined from light and small-angle X-ray scattering and viscosity measurements in tetrahydrofuran at 25 degrees C. The obtained data were compared with modern theories for the wormlike star. The experimental P(q) data were represented by the wormlike star model connected with a universal joint. The other data were comparably explained by the same model.