Infrared Spectroscopic Characterization of Polymer and Clay Platelet Orientation in Blown Films Based on Polypropylene‐Clay Nanocomposite

Abstract

Abstract The “tilted film” transmission infrared spectroscopy method was used to characterize the biaxial orientation in a set of blown films containing polypropylene (PP), layered silicate nano‐reinforcement, and two different compatibilizing agents based on maleic‐anhydride‐grafted PP. Both interactive spectral subtraction and peak fitting were used to determine trichroic ratios. The biaxial orientation of the polymer chains could be clearly quantified according to well‐established relationships for PP. In addition, the clay platelet orientation could be determined from the trichroism of the SiO stretching bands around 1100 – 1000 cm −1 . The clay orientation was found to be quite high (Hermans orientation function around +0.8) and was not significantly affected by the presence of compatibilizing agent.