Nano clay reinforced xylan barriers

Birch wood xylan, plasticized with glycerol and reinforced with a nano clay, bentonite, was coated onto paper as a barrier layer. Bentonite increased the viscosity of plasticized xylan solutions, which had a positive influence on coating ability. X-ray diffraction traces of the xylan bentonite coatings confirmed that the interlayer distance of the bentonite particles had increased indicating that the xylan and/or glycerol resides in the interlayer region. The water vapour barrier properties were enhanced by dispersing bentonite into the glycerol-plasticized xylan coating. The improvement in properties varied from moderate to significant (340 to 56 g m-2 d-1). The permeability of diagnostic aroma compounds also decreased. Scanning electron micrographs confirmed that the best xylan-glycerol-clay coatings were intact without any pinholes