Synthesis, spectroscopic characterization and optical studies of poly(AN-co-St) composites with doped lanthanum (III) chloride for aerospace applications

In this study, firstly, the copolymer of acrylonitrile (AN) and styrene (St) was synthesized by solution polymerization method using 2,2′-azobisisobutyronitrile (AIBN) as an initiator. The composites of copolymer incorporating lanthanum (III) chloride (3, 6, 9 and 18 wt%), the rare earth element (REE), were prepared and thin films were produced by thermal evaporation method for optical measurement. The samples were characterized by attenuated total reflectance Fourier transform infrared (ATR–FTIR), scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS) and X-ray diffraction (XRD). The glass transition temperature, which is one of the thermal properties of the synthesized copolymers and composites, was examined with a differential thermal analyzer. The changes in the optical properties of the samples produced with LaCl3 dopant were investigated using the UV–VIS spectroscopy. The optical band gaps of the samples were calculated using Tauc equation. As a result of the optical studies, it was observed that there was a change in the conductivity properties of the samples with the addition of LaCl3. The present results showed the advantage of using LaCl3 as a filler to improve the optical properties of poly(AN-co-St) samples.