Infrared spectra of the main optical properties of poly(methyl methacrylate) thin films

This study aimed to determine the infrared (IR) spectra of the main optical properties of poly(methyl methacrylate) (PMMA). This is a simple and original method for obtaining spectra of the main optical properties from the reflection-absorption spectrum. Infrared reflection spectra of the main optical properties of PMMA were obtained from the complex relative permittivity using the Drude-Lorentz model for permittivity. Classical dispersion analysis of the reflection-absorption spectrum of poly(methyl methacrylate) films cast on a metal mirror was performed. The method is based on an iterative least squares fitting process of the experimental reflection-absorption spectrum of the polymer with the corresponding theoretical spectrum obtained from the complex permittivity Drude-Lorentz model. This approach is original for obtaining the relative permittivity and subsequently obtaining the main optical properties of the polymer film: complex electric modulus, energy loss function, optical constants, absorption coefficient, penetration depth, dissipation factor, and complex optical conductivity. In addition to the findings of other articles, some optical properties of PMMA films have been presented, which may be useful for studying PMMA-based composites or copolymers.