Improvement of optical properties and thermal stability of poly vinyl alcohol using salicylic acid confined in nanohybrid material

This study aims to benefit from the confinement of salicylic acid in the nanoscale to convert poly vinyl alcohol to be UV absorber. Therefore, Zn-Al LDH was prepared and used as a host. It intercalated with salicylic acid which used as a guest to form nanohybrid material. This nanohybrid material was inserted inside poly vinyl alcohol to build nanocomposite material. X-ray diffraction results and electron microscopy images showed that the interlayer spacing of Zn-Al LDH increased from 0.77 to 1.55 nm after intercalation reaction with salicylic acid. The thermal analyses revealed the presence of a complex system of supra-molecular host-guest interaction. The optical properties of Zn-Al-salicylate nanohybrid material showed new absorption bands in the UV region comparing with the absorption bands of salicylic acid sodium salt. Nanocomposite based on both Zn-Al-salicylate nanohybrid and PVA were characterized by X-ray diffraction, Scanning electron microscopy, UV-Visible absorption spectra, and thermal analyses. The experimental results suggested that the nanocomposite was formed via exfoliated structure and the nanohybrid layers were completely and uniformly dispersed in a continuous polymer matrix. By comparing with the thermal and optical properties of the original PVA, the PVA nanocomposite became more stable and UV absorber.