abstract
Paperboard is an environment -friendly multi -layer material widely used for packaging applic a- tions. However, for food packaging paperboard lacks essential barrier properties towards oxygen and water vapor. Conventional solutions to enhance these barrier properties (e.g. paperboard film coating with synthetic polymers) require special manufacturing facilities and difficult the end -of - life disposal and recycling of the paperboard. Paperboard coating with silica -based formulations is an eco -friendly alternative hereby disclosed. Silica -nanocoating s were prepared by sol -gel synth e- sis, with or without the addition of Zn(2) -Al -NO 3 layered double hydroxides (LDHs), and applied on the surface (ca 2 g/m 2 ) of industrial paperboard samples by a roll -to -roll technique. The ph y- sicochemical features of silica -nanocoatings were studied by FTIR -ATR, SEM/EDS, XRD analysis and surface energy measurements. The barrier properties of uncoated and silica -coated pape r- board were accessed by water vapor transmission rate (WVTR) and oxygen permeability ( J O 2 ) measurements. The best barrier results were obtained for paperboard coated with a mixture of tetraethoxysilane (TEOS) and 3 -aminopropyltriethoxysilane (APTES), with and without the in- corporation of LDHs.
authors
Vänia M. Dias, Alena Kuznetsova, JoÜo Tedim, Aleksey A. Yaremchenko, Mikhail L. Zheludkevich, Ins Portugal, Dmitry V. Evtuguin