Transparent Copolyester/Organoclay Nanocomposites Prepared by In Situ Intercalation Polymerization:Synthesis, Characterization, and Properties

摘要

In this study, amorphous poly(ethylene terephthalate-co-1,3/1,4-cyclohexylenedimethyIene terephthalate) (PETG)/ organoclay nanocomposites was synthesized by the in situ intercalation polymerization of terephthalic acid, ethylene glycol, 1,3/1,4-cyclohexanedimethanol, and organoclay. The organoclay was obtained by modifying sodium montmorillonite (clay) with hexadecyl tri-phenylphosphonium bromide. The thermal, mechanical, optical, and gas barrier properties of these PETG nanocomposites with various organoclay contents (0-3 wt%) were discussed. The differential scanning calo-rimetry and X-ray analyses revealed that all of the nanocomposites were amorphous. X-ray diffraction and transmission electron micrographs showed that the organoclay was well dispersed in the polymer matrix, although some parts of the agglomerated layers remained on the scale of several hundreds of nanometers. The thermal stability and the mechanical property of the nanocomposites increased with organoclay content. The optical transmittances of nanocomposites that contained 0.5, 1, and 3 wt% of organoclay were 86.8%, 84.4%, and 77.4%, respectively. The oxygen transmission rate of the nanocomposite that contained 3 wt% of organoclay was about 50% of the PETG base polymer.