Effect of cationic-surfactant-modified Saudi bentonite on the thermal and flammability properties of poly(vinyl alcohol)-based nanocomposite films

ABSTRACT

In this study, poly(vinyl alcohol) (PVA)-modified Saudi bentonite nanocomposite films were prepared using the solution method. Two surfactants, cetylpyridinium chloride and tetrabutyl phosphonium bromide, were used to modify the clay after the ion-exchange process by Na⁺ ions. The effect of the addition of modified Saudi bentonite (2.5%) on the thermal and flammability properties of the nanocomposite films was investigated. The prepared samples were characterized using Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Thermogravimetric analysis and differential scanning calorimetry were carried out to observe the thermal behaviour of the PVA-based nanocomposite films. Vertical flammability tests (UL94 VB) were also carried out to study the flame retardancy behaviour of the nanocomposite films. The nanocomposite films showed better flammability than pure PVA, wherein the ignition time of the nanocomposites increased and flame propagation rate decreased. The thermal stability of the nanocomposites increased by approximately 10% for the onset and endset temperature of decomposition. The type of surfactant played an important role in dispersion of the clay into the polymeric matrix and enhancing the flammability properties of the films wherein the tetrabutyl phosphonium bromide was better flame retardant than cetylpyridinium chloride.

KEYWORDS:

• Nanocomposites
• poly(vinyl alcohol)
• thermal properties
• flammability properties
• surfactant

Acknowledgements

Mashael Alshabanat designed, performed some parts of experiments, analysed the results, wrote the paper and revised it. Mrefah AL-Anazy performed the other parts of experiments, wrote some parts of paper and revised it.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Mashael Alshabanat http://orcid.org/0000-0001-5378-824X

Mrefah AL-Anazy http://orcid.org/0000-0001-7386-5820

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.