Chemometric optimization of PVA nanocomposites: Synergistic effects of CNT, Cu, HEC-Ac, and hyperbranched polymers on mechanical properties

Abstract

This paper presents a novel approach to the custom design of polyvinyl alcohol (PVA) based nanocomposites, by using chemometric methods to identify optimal proportions of organic/inorganic reinforcements that enhance mechanical properties such as flexibility and strength. Employing material characterization techniques, such as scanning electron microscopy (SEM), confocal laser microscopy (CLSM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS), we elucidate the synergistic effects of hyperbranched polyester polyol polymers (Boltorn®H20), hydroxyethylcellulose with citric acid (HEC-Ac), carbon nanotubes (CNT), and Cu microparticles on the mechanical behaviour of PVA nanocomposites. The incorporation of CNT and Cu into a PVA (Young’s modulus: 5.4 GPa) increases stiffness by 30 %, which rises to 54 % with the addition of the H20 hyperbranched polymer. Our findings demonstrate that the incorporation of CNT, Cu, H20, and HEC-Ac at their maximal amounts in PVA allows the development of a hard material with a high capacity for strain-induced hardening. Conversely, the exclusion of Cu in these nanocomposites yields a soft material with an enhanced capacity for hardening. Furthermore, it would be feasible, for instance, to develop a coating for a flexible circuit by incorporating CNT, HEC-Ac, and H20. This material would be highly flexible and resilient, but under tensile stress, its behaviour would change, hardening to protect the circuit. This innovative methodology enables the customisation of nanocomposite properties to meet specific application needs, such as protective coatings for flexible circuits. Ultimately, the study underscores the innovative potential of multivariate design and chemometric techniques in enhancing the mechanical properties of PVA-based nanocomposites, paving the way for their application in diverse industrial and biomedical fields.