Nov_Dec_AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | N O V E M B E R / D E C E M B E R 2 0 2 0 2 1 M ultilayered materials are com- monly used across various sec- tors, such as the packaging, con- struction, and medical industries. How- ever, multilayered structures may alter the mechanical, acoustic, and optical properties of these materials. Identi- fying the chemical composition of dif- ferent layers by studying the cross section of a multilayered film is import- ant in the research and development of composite materials. With the aid of a microscope and FTIR spectrophotom- eter, infrared spectra can be acquired with spatial resolution on the order of 10 microns along the cross section of composite films. The following study demonstrates that analysis of the FTIR spectra can help clarify and explain the formulation of different layers that compose the polymer film. EXPERIMENT DETAILS An FTIR microscope was set up in combination with an FTIR spectropho- tometer (Table 1). The compatible soft- ware suites were used to maneuver the microscope and to set the experiment’s parameters. Mapping software enabled scanning and measuring samples in the points, line, or area modes. The line mode was used to investigate the cross section of a film sample. By setting an appropriate aperture size, an optimal signal was obtained while maintaining high spatial resolution over the cross section of the composite films. Sample preparation was of vi- tal importance in this experiment. The composite filmunder study came froma commercial source. It was white in color and laminated on both sides. The sample was first cut to a smaller size of approximately 0.5 x 0.5 cm. It was then loaded onto a microtome and cut into thin slic- es, (Fig. 1), which were subsequently loaded onto a diamond window under a binocular optical microscope. The sam- ple was then transferred to the FTIR mi- croscope for infrared investigation. The front and back sides of the film have different chemical composi- tions. FTIR spectra of both sides were acquired by using an attenuated total CHARACTERIZING POLYMER FILMS WITH FTIR MICROSCOPY Using a Fourier transform infrared (FTIR) microscope along with an FTIR spectrophotometer proves beneficial in analyzing the complex layers of some composite polymer films. TECHNICAL SPOTLIGHT TABLE 1 — EXPERIMENT PARAMETERS Parameter Value Instrument Shimadzu AIM-9000 FTIR microscope Shimadzu IRTracer-100 FTIR spectrophotometer Ge ATR accessory for AIM-9000 FTIR microscope Optical mode Absorbance, reflectance, ATR Detector Mid-band MCT detector with liquid nitrogen cooling Spectral range 4000-7000 cm -1 Resolution 8 cm -1 Number of scans 64 Fig. 1 — The composite filmwas loaded onto a microtome and cut into thin slices for cross section studies. Slices were loaded onto a diamond window and transferred to the microscope. Fig. 2 — FTIR spectra of the two sides of the polymer film sample. One side (red) is polyethylene; the other (black) is 84% petrothene NA 117 and 16% polyamide.