Blends containing chitosan and poly(sodium-4-styrene sulphonate). Compatibility behavior

The phase behavior of blends containing chitosan (CS) and poly(sodium-4-styrene sulphonate) (PSS) was analyzed by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR), dielectric spectroscopy (DRS) and atomic force microscopy (AFM). FTIR and DRS analysis seem to indicate the existence of interactions between sulphonate groups of PSS and -NH₂ or -OH or both groups of CS. The study of blends by AFM showed a completely different morphology when compared with that of pure components as nanocrystalline domains appeared as globular agglomerates containing more or less spherical particles instead of the independent nanodomains seen in the neat components, possibly as consequence of interactions between both polymers.