Fourier Transform Infrared Spectroscopy FTIR is a powerful analytical technique used to identify the chemical composition of various materials, including polymers. It works by measuring the absorption of infrared radiation by the sample at different wavelengths, which provides information about the molecular structure and functional groups present in the sample. Here's how FTIR can be used to identify the chemical composition of a polymer sample:1. Sample preparation: First, the polymer sample needs to be prepared in a suitable form for FTIR analysis. This can be done by creating a thin film of the polymer or by mixing it with an infrared-transparent matrix, such as potassium bromide KBr , to form a pellet.2. Infrared radiation: The prepared sample is then placed in the FTIR spectrometer, which exposes it to a broad range of infrared wavelengths. The sample absorbs specific wavelengths of the infrared radiation, corresponding to the vibrational frequencies of the chemical bonds in the polymer.3. Interference pattern: The transmitted or reflected radiation from the sample is collected and combined with a reference beam that has not interacted with the sample. This creates an interference pattern, which is recorded by a detector.4. Fourier Transform: The interference pattern is then processed using a mathematical technique called Fourier Transform, which converts the raw data into a spectrum showing the intensity of absorbed radiation as a function of wavelength or wavenumber .5. Interpretation of the spectrum: The resulting FTIR spectrum contains characteristic peaks that correspond to the vibrational frequencies of specific functional groups and chemical bonds in the polymer. By comparing the peaks in the spectrum with reference spectra of known compounds, the chemical composition of the polymer can be identified.6. Quantitative analysis: In some cases, the intensity of the peaks in the FTIR spectrum can be used to determine the concentration of specific components in the polymer sample. This requires the use of calibration curves or other quantitative methods.In summary, FTIR is a valuable tool for identifying the chemical composition of a polymer sample by analyzing the absorption of infrared radiation at different wavelengths. By interpreting the resulting spectrum and comparing it with reference spectra, the presence of specific functional groups and chemical bonds can be determined, providing insight into the molecular structure and composition of the polymer.