EFFECTS OF FORMATION AND PENETRATION PROPERTIES OF BIODEGRADABLE CHITOSAN/MONTMORILLONITE FILM ON THE BARRIER OF PACKAGE PAPER

摘要

The conventional package paper was coated with biodegradable chitosan/montmorillonite composites,in order to extend the application scope of paper,as well as replacing plastic packaging materials to meet the environmental and storage requirement of packaging material in the packaging industry.The chitosan/montmorillonite nanocomposites were prepared by the solution intercalation method which montmorillonite was used as nanofiller and diluted acetic acid was used as solvent for dissolving and dispersing chitosan and montmorillonite.In the current research the effect of montmorillonite dispersion rate,the content of montmorillonite and dispersant in the mixed solution,the coating weight on the surface and penetration properties of chitosan/montmorillonite nanocomposites coated paper were being investigated.The surface properties of the coated paper were observed by using Scanning electron microscope(SEM)and Atomic force microscope(AFM).The water permeation and water vapor barrier properties were confirmed through penetration dynamics analyzer(PDA)and water vapor permeability tester(WVP),respectively.It was founded that chitosan and chitosan/montmorillonite nanocomposites could improve the paper smoothness and reduce the paper roughness.Compared with the chitosan and chitosan/montmorillonite nanocomposites,the chitosan/montmorillonite nanocomposites had a poorer formation than the single chitosan,but it had low water permeability and better water vapor barrier properties.The paper coated with the lower content of montmorillonite,or with the high montmorillonite dispersion speed and the content of dispersant had better smoothness and elongation.Additionally,the coated paper had excellent barrier properties under the conditions of high montmorillonite and dispersant content,high montmorillonite dispersion rate and high coating weight.The existence of montmorillonite in chitosan matrix had positive effect on the barrier properties of the coated paper.