Reinforcement of Poly(vinyl alcohol) using hydrogen bonding of carboxylic acid-functionalized graphitic nanoplatelets

In this study, as a filler, carboxylic acid-functionalized graphitic nanoplatelets (COOH-GN) were used to enhance the mechanical properties and thermal stability of poly(vinyl alcohol) (PVA), and COOH-GN/PVA_X nanocomposites were prepared easily with the solution mixing method into water due to very good dispersion of COOH-GN. The COOH-GN/PVA_X nanocomposites exhibit remarkable mechanical properties and thermal stability to compare with pure PVA because of the excellent distribution of the COOH-GN into the PVA matrix and the strong interfacial adhesion and hydrogen bonds between the PVA and COOH-GN. The COOH-GN/PVA_2 nanocomposite exhibits superlative mechanical and thermal properties. Especially, its tensile strength, Young's modulus, tensile toughness, and elongation are increased by 49.0, 25.8, 118.8, and 53.1% compared with pure PVA, respectively. Thus, the graphitic nanoplatelets (GnPs) in this study can be controlled by the functional groups, have excellent properties and are cost-effective. Moreover, the GnPs can be used as a reinforcing filler for hydrophobic and hydrophilic polymers.