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

Mashael Alshabanat,Murefah Al-Anazy

doi:10.1080/16583655.2019.1579295

Mashael Alshabanat, Murefah Al-Anazy

Open Access

https://doi.org/10.1080/16583655.2019.1579295

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Abstract

ABSTRACTIn 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.

Highlights

Over the past few decades, the polymer industry has developed rapidly owing to the extensive use of polymers for a wide range of applications
The results suggest the efficient intercalation of poly(vinyl alcohol) (PVA) into the layers of clay, and this seems to agree with the X-ray diffraction (XRD) and Scanning electron microscopy (SEM) results, which showed better intercalation and dispersion of BS2 particles throughout the polymeric matrix in the PVA/SB2 sample compared with the others
PVA was used as a matrix to prepare nanocomposite films with modified Saudi bentonite

Summary

Introduction

Over the past few decades, the polymer industry has developed rapidly owing to the extensive use of polymers for a wide range of applications. The development of novel polymeric materials such as polymer nanocomposites with unique properties has gained immense attention. Such composites are prepared by incorporating nanoparticle fillers into polymer matrices. I.e. they can be ignited by external heat. Their combustion produces smoke and toxic gases. Many efforts have been made to reduce the flammability of polymers and decrease the emission of toxic gases during combustion

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