An advanced preparation and characterization of the PET/MgAl-LDH nanocomposites

Abstract

A new nanocomposite poly(ethylene terephthalate)/sulfanilic acid salt-modified layered double hydroxide (PET/MgAl LDH-SAS) was synthesized by an in situ polymerization method using MgAl LDH-SAS as a catalyst. This study employed a magnesium–aluminum layered double hydroxide (MgAl LDHs) with various particle sizes, which was modified by sulfanilic acid salt (SAS) through the hydrothermal process to form the MgAl LDH-SAS, and then intercalated by bis-hydroxy ethylene terephthalate (BHET) to form PET/MgAl LDH-SAS. Because of MgAl LDH-SAS, catalytic activity increased the polymerization rate, and nanocomposites also exhibited good thermal stability without the decomposition during the PET polymerization. The results indicated that the modified MgAl LDH-SAS improves the interlayer compatibility between the PET and MgAl LDH-SAS layers, thus making it easier for the oligomer to enter the gallery of MgAl LDH-SAS layers. Thus, the polymer chains can be included between the LDHs layers during the polymerization of the polymer matrix. The gas barrier, thermomechanical properties, and crystallization behavior of these new types of PET nanocomposites are investigated.