<scp>Size exclusion chromatography</scp> characterization of poly (ether ether ketone), <scp>PEEK</scp>, after chemical modification

Characterization of the molar mass distribution (MMD) poly (ether ether ketone) (PEEK) is very troublesome due to insolubility PEEK in common solvents. The solubility may be substantially improved after its sulfonation. Sulfonated (SPEEK) was prepared by sulfonation with 98% concentrated H2SO4 at room temperature. presence sulfonic acid group (-SO3H) matrix confirmed nuclear magnetic resonance and Fourier transform infrared spectroscopy. degree (DS ~ 95%) determined proton deuterated dimethyl sulfoxide thermal analysis methods. equivalent MMD sulfonated 30°C three polar solvents (N,N-dimethylacetamide, N,N-dimethylformamide N-methyl-2-pyrollidone) PS/DVB column using calibration PMMA standards. A salt (LiBr) added for suppression undesired interactions analytes packing. Moreover, sulphonated separated size exclusion chromatography (SEC) coupled a multi-angle light scattering (MALS) detector. It found that absolute average SPEEK from MALS detection much closer value measured SEC N,N-dimethylacetamide +LiBr than values N-methyl-2-pyrollidone.