Understanding the role of dye in colorful thermoplastic film under visible light

Abstract

Polystyrene is a thermoplastic that is widely used in industry to manufacture of various materials. In this work, the objective was to investigate the effect of the Crystal Violet (CV) dye on polystyrene films under visible light. The films were produced by the casting method. Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and viscosimetry were used to monitor the effect of radiation and 1H Nuclear Magnetic Resonance (1H-NMR) was employed to evaluate the interaction between the polymer and the dye. Carbonyl Index confirmed that oxygenated species were formed during exposure to light and photo-oxidation is the major mechanism involved in CV-sensitized PS degradation. The variations in relaxation times indicated that electrostatic attraction is the main form of interaction between the materials involved and molecular dynamics calculations confirm the 1H-NMR results. The CV dye could initiate degradation reactions and acted as an efficient photosensitizer in PS matrices.