FT-IR Image Processing Algorithms for In-Plane Orientation Function and Azimuth Angle of Uniaxially Drawn Polyethylene Composite Film

The FT-IR imaging method has been applied to acquire thousands of infrared spectra at a spatial resolution near the diffraction limit using an IR image sensor. We propose the mathematical procedure to visualize the degree of molecular orientation and the azimuth angle of the orientation axis using the polarized absorbance images measured with a linear polarizer settled at four different angles. It mathematically synthesizes in-plane orientation function that is independent of the direction of the incident polarization and visualizes the molecular orientation and the azimuth angle using an IR imaging sensor. By introducing the azimuth angle image, a small change of the molecular orientation can be detected visually in the early stage of local deformation of the uniaxially drawn process of the polyethylene composite film.