Effect of H-bond active sites on transport properties of poly(ethylene oxide) dissolved in its monomers: Shear viscosity and diffusion coefficient studies

Abstract

The possibility of dissolving poly(ethylene oxide) [PEO:H–(O–CH2–CH2)n–OH] in its monomeric liquid ethylene glycol [EG:H–(O–CH2–CH2)–OH] represents the only way to verify the complex polymer–monomer interactions, through the OH end groups, resulting in the scaling law R∝Nν. We report viscosity results, in conjunction with photon correlation spectroscopy data, on different molecular weight PEO samples, in a wide range of concentrations, dissolved in EG. In order to distinguish among various interaction mechanisms, we also studied PEO dissolved in EG monomethyl ether [EGmE:CH3–(O–CH2–CH2)–OH] and EG dimethyl ether [EGdE:CH3–(O–CH2–CH2)OCH3], the latter not having in its chemical structure OH hydroxylic groups available to give rise to hydrogen bond interactions. In particular, the quality (good-theta-poor) of the solvents has been analyzed by verifying the well-known Mark–Houwink–Sakurada scaling law and the effects of the polymer–solvent interactions on the coils diffusive properties.