Diels–Alder Hyperbranched Pyridylphenylene Polymer Fractions as Alternatives to Dendrimers

Abstract

The results of the hydrodynamic study of hyperbranched pyridylphenylene polymers synthesized via Diels–Alder cycloaddition reaction of multifunctional monomers are reported. The synthesized polymers were fractionated into a much narrowly dispersed fractions. The in-depth analysis of molecular characteristics and conformation of the initial polymers and corresponding fractions was performed using the unique combination of hydrodynamic approaches. The intercorrelation and self-consistency of obtained data were ensured using the hydrodynamic invariant concept and classical Kuhn–Mark–Houwink–Sakurada scaling relations. The evaluated data suggest that hyperbranched pyridylphenylene demonstrates the hydrodynamic behavior typical for asymmetrical compact macromolecular species. Furthermore, hydrodynamic characteristics of herein studied hyperbranched pyridylphenylene polymer fractions were compared with known hydrodynamic data for pyridylphenylene dendrimers. Nearly identical hydrodynamic behavior was found for the compared macromolecules, especially for low molecular mass fractions, which may suggest that the fractionation of hyperbranched polymers results in dendrimer-like structures. The oblate ellipsoid model provides reasonable correlation between hydrodynamic properties of hyperbranched pyridylphenylene polymer fractions and pyridylphenylene dendrimers.