Effect of isomer on polymer blends miscibility: A synchrotron small angle X-ray investigation

Abstract

We use synchrotron small angle X-ray scattering (SAXS), calorimetry and cloud point measurements to investigate the thermodynamic of mixing in blends of poly(cyclohexyl acrylate) with the ortho and meta isomer of poly(bromostyrene) [P2BrS, P3BrS]. PCHA is miscible with P2BrS and P3BrS with lower critical solution temperature (LCST). Measurements of the absolute scattered intensity enable determination of the Flory-Huggins χ-parameter within the framework of the de Gennes random phase approximation. The following order is observed: χ(PCHA/P2BrS)<χ(PCHA/P3BrS). © 1998 Elsevier Science Ltd