Orateur
Description
Abstract – Poly(vinyl chloride) (PVC)-Maghnite nanocomposites were prepared by melt blending using a two-roll mixer. This study aims to evaluate the effect of incorporating a natural Algerian clay, Maghnite, extracted from the Roussel deposit in Maghnia (northwest Algeria), on the properties of PVC. This nanofiller was incorporated at low contents (1 to 4 phr) in two forms: raw (RMMT) and modified (OMMT) with a surfactant, hexadecylamine. The properties of PVC-Maghnite nanocomposites were studied using several physicochemical techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and light transmission. Their resistance to degradation was also evaluated.
XRD analysis of the two nanofillers (RMMT and OMMT) revealed an increase in the interlayer spacing of Maghnite, from 1.26 nm (2θ = 7°) to 2.69 nm (2θ = 3.27°) after modification with hexadecylamine chloride. This increase confirms the intercalation of hexadecylammonium ions between the Maghnite layers through a cation exchange process, as represented by the following reaction:
Phyllosilicate-Na⁺ + C₁₆H₃₃NH₃⁺Cl⁻ → Phyllosilicate-H₃N⁺C₁₆H₃₃ + NaCl
Furthermore, XRD and SEM analyses of the nanocomposites showed that the modified Maghnite is well dispersed and exfoliated within the PVC matrix. The TGA results, combined with thermal stability studies and light transmission tests, demonstrated that the incorporation of OMMT significantly enhances the thermal stability of PVC due to its barrier effect, which limits the diffusion of heat and volatile decomposition products. Additionally, the modified Maghnite improves the light transmission (UV, visible, and IR) of the nanocomposites compared to pure PVC and composites containing unmodified Maghnite.
Keywords – PVC; Raw Maghnite; Modified Maghnite; Nanocomposites; Physical properties.
