Polyoxymethylene-based nanocomposites with montmorillonite: An introductory study

Abstract

Nanocomposites of polyoxymethylene (POM) and organo-modified montmorillonite were obtained by melt mixing method and investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and mechanical testing, respectively. The XRD results indicated mixed tactoid-exfoliated structure of the obtained nanocomposites; introduction of montmorillonite (MMT) was found to strongly influence the crystalline structure of POM through altering of nucleation mechanism. Layered silicate-modified POM exhibited improved tensile strength and modulus as well as increased elongation, unlike common polymeric microcomposites that reach higher modulus at the expense of ductility. Nanoadditives contribute to the formation of a core-shell morphology of injection-moulded samples that was ascribed to increased elongation at break of nanocomposite materials. Both mechanical and thermal properties of nanocomposites varied depending on type of ammonium surfactant used for organomodification of MMT.