A spectrophotometric study of hydrogen bonding in methylcellulose-based edible films plasticized by polyethylene glycol

With the use of Fourier Transform Infrared (FTIR) analysis applied to methy lcellulose (MC) films, the hydrogen bonding formation between MC-MC molecul es and between MC and a series of different-molecular-weight PEGs was studi ed. The spectra of the films were interpreted in terms of the symmetry dist ortion of hydroxyl stretch at 3466.5 cm(-1), which is the measure of hydrog en bonding intel actions in the polymer matrix. The symmetry distortion was determined to be affected by the MC concentration, indicating the presence of intra- and intermolecular hydrogen bonding between MC molecules. Neithe r ethanol nor its concentration influenced the symmetry distortion. A compe tition for hydrogen bonding via hydroxyl groups between MC-MC and MC-PEG oc curred when PEG was incorporated into the polymer matrix.