Abstract

The permeability of polymer is determined by its chain configuration, phase morphology and the interaction with the
penetrant. Based on these principles, the permeability of the polyester of poly (ethylene terephthalate)(PET) is enhanced
through different modifiers in order to apply it to barrier packing bottle. In this paper, poly (m-xylylene
adipamide-terephthalyl amide) (MXD6T) and nanometer silicon dioxide (SiO2) nanocomposite with SiO2 load from 5%
to 20% (by mass) is prepared and used to improve the barrier property of polyester bottle materials. In preparing
MXD6T-SiO2 (NMXD6T), silica is in-situ polymerized with hexane diacid, terephthalic acid (TPA), alkyl and aromatic
diamine. The different molar ratio of hexane diacid to terephthalic acid with the same molar diamine is designed to give
the composites with different viscosity, thermal performance and the barrier properties. The 3-8 times of enhanced
permeability of these polyester matrix nanocomposites with this NMXD6T to pure polyester resins are reported.
The relationship of NMXD6T’s configuration and the permeability properties of polyester nanocomposites are
characterized by techniques of the dynamic scanning calorimeter (DSC), FT Infrared, and Transmission Electronic
Microscopy (TEM). DSC shows that NMXD6T is totally amorphous. FTIR shows the existence of silicon-oxygen bond
formed in the nanocomposite, and TEM indicates an average size from 30nm to 100nm of SiO2 particles being phase
separated from MXD6T matrix, while well bonded to the polyester chains. It is concluded that the NMXD6T-PET
nanocomposites may be one of the best way to enhance the barrier properties of polyesters for their packing application.

This work is licensed under a Creative Commons Attribution 4.0 License.