Thermal and Morphological Properties of Poly(vinyl alcohol) and Layered Double Hydroxide (LDH) Nanocomposites

Abstract

Poly(vinyl alcohol) (PVA)/layered double hydroxide (LDH) nanocomposites were synthesized with different compositions: 0, 2, 4, 6, and 8 wt% of LDH by the solution intercalation method. The effects of the layered double hydroxide platelet concentration on the properties of the PVA/LDH films were investigated by thermogravimetric analysis (TGA), optical microscopy, and Fourier transform infrared spectroscopy (FTIR). A reduction in the onset of thermal decomposition temperature was observed in PVA/LDH composites compared to neat PVA. The reduction in the onset of thermal decomposition was likely due to a nucleophilic attack mechanism. The presence of single LDH sheets in form strips in the optical micrographs shows direct evidence of exfoliation, indicating that LDH layers were well-exfoliated and dispersed in the PVA matrix in a disorderly fashion. The FTIR analysis showed good interaction between the continuous PVA matrix and the LDH nanoparticle fillers, by hydrogen bonding through hydroxyl groups. The primary focus of the present investigation was to explore the potential of LDH material as a nanofiller and to improve dispersion of LDH in polar polymers like PVA.