Interaction and miscibility study of fumarate-based macromers with chitosan

This work is aimed to prepare Chitosan/Poly(ethylene glycol fumarate) (Ch/PEGF) blend films and to determine blend miscibility of the two polymers as a function of molecular interactions between Ch and PEGF. The blend films are prepared in various ratios (0/100 to 100/0) by the conventional solution-casting method. Interactions occurring in the blends are investigated and probed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA). FTIR and XRD analyses reveal the existence of newly-formed hydrogen bond interactions between Ch and PEGF. The influence of Ch/PEGF blend ratio on thermal properties of the blend systems is discussed especially considering thermal stability. The results indicate that both melting point and crystallinity of PEGF component in the blends depend on the composition of the blends. The obtained results of FTIR, DSC, and XRD analyses suggest that the partially protonated amine groups of Ch interacts with the hydroxyl groups of PEGF and thus partial miscibility are occurred. The results are confirmed with polarized microscopy observations. It is shown that although weak hydrogen bonding exists between the polymers functional groups; the blends are partially miscible. Highlights: ► Miscibility of Ch/PEGF blends is evaluated as a function of molecular interactions. ► We explore the relationship between blend ratio of films and miscibility behavior. ► Chitosan chains can affect and disturb original crystalline structures of PEGF. ► Thermal stability of the blend films is discussed. ► These analyses suggest the blends are partially miscible