Reduced viscosity, rheology and morphological properties of sulfonated poly (ether ether ketone): Polyetherimide blends

Blends of poly (ether ether ketone) (SPEEK) and polyetherimide (PEI) were prepared in five different weight ratios, using N,N-dimethylacetamide (DMAc) as solvent. Reduced viscosity and rheological parameters of these blends were investigated. Cannon–Fenske viscometer was used to study the viscoelastic parameters of the salt-free polyelectrolyte blends and the data obtained was fitted in Fuoss–Strauss equation. Effects of temperature and concentration have been investigated. It was observed that the storage modulus (G′) and dynamic viscosity (η′) of the blends varies significantly as compare to pure SPEEK and PEI. Surface morphology and thermal behavior of the membranes were studied using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Form SEM results it was observed that the phase separation occurs at 25% PEI contents in blends.