Transparent clay-polymer hybrid coatings on PET film

The PVA/LAP/MMT coating endowed PET film with improved flame retardancy and oxygen barrier. Image source: HG-Fotografie - Pixabay.

A multifunctional nanocoating, consisting of montmorillonite (MMT) / laponite (LAP) / polyvinyl alcohol (PVA), was deposited onto the surface of polyethylene terephthalate (PET) film via a facile co-assembly process.

Improved flame retardancy
As a result, the PVA/LAP/MMT coating endowed PET film with improved flame retardancy and oxygen barrier. At 4 layers deposition of PVA/LAP/MMT, the film maintained more than 90% transmittance to the visible light. The microscale combustion calorimetry revealed, compared with control PET sample, the peak of heat release rate and total heat release of PET@(MMT/LAP/PVA)4 sample were reduced by 67.4% and 45.3%, respectively.

The oxygen transmission rate significantly reduced at the same time. The reason was speculated at the combination of MMT and LAP, a more compact shielding layer was formed on the PET substrate.