Co‐Crystalline Phases of Syndiotactic Polystyrene with Azelaic Acid Molecules of Pharmaceutical Interest

Sorption of dicarboxylic acid molecules of pharmaceutical interest such as azelaic acid (AzA), in syndiotactic polystyrene (sPS) films presenting δ and ϵ nanoporous crystalline structure, is reported. Fourier Transform Infrared (FTIR), Polarized FTIR and Wide-Angle X-ray diffraction (WAXD) patterns on axially oriented sPS films has been performed to verify their sorption in crystalline lattices resulting in the formation of co-crystalline (CC) phases. Experimental evidence provides that AzA molecules can be included in the crystalline nanochannels of ϵ phase both as isolated and hydrogen-bonded molecules whereas they are only dissolved in the amorphous phase of δ samples