Study On Preparation Of PVA Coatings And Application On The Paper Packaging Materials

The subject of the paper is to prepare PVA/OMMT nanocompositesfor coating, which based on PVA polymers that filled withorganic-modified silicate layers in nanoscale dispersion, plasticizer, anddefoamer. Finally, the PVA/OMMT nanocomposites were chemicallymodified through crosslink reaction. In the application stage, the Kraftpaper and cardboard paper were coated by PVA coatings, a high barriercoating layer was obtained after drying. The results show that the barrierand properties of the coated paper are excellent, and the physical propertieswere improved, with it main contents summarized as follows:Firstly, Ca-montmorillonite was modified with Single-chainquaternary ammonium, after that double-stranded quaternary ammoniumwas used to prepare the so-called secondarily-intercalatedmontmorillonite.The influence of different cation exchange capacity (CEC)of agents on the organic intercalation was explored. The as-preparedsamples were characterized by the X-ray diffraction, Fourier-transforminfrared, and thermo gravimetric–differential thermal analysis. Resultsshow that the basal spacing of secondarily-intercalated montmorilloniteincreased with the CEC of intercalation agents, and double-strandedquaternary ammonium was intercalated into the montmorillonite, whichplayed an important role in the increasing of lnterlamellar space.Secondly, PVA/OMMT nanocomposites were prepared bysolution-intercalation. Through the single factor experiment, thePVA/OMMT nanocomposites material performance was inspected by thedifferent content OMMT, plasticizer and crosslinking agent. The structureof PVA/OMMT nanocomposites was characterized by means of XRD,SEM and TEM. The result revealed that, the interlayer space of MMTincreased after composing with PVA, which indicated that the PVA chainshad intercalated into the galleries of OMMT. Along with the increase of thecontent of glycerin, the moisture content of PVA/OMMT nanocompositesincreased. When plasticizer content is9%, the environment relativehumidity was70%, moisture content reached5.96%, and the viscositydecreases with the increase of the content of plasticizer. The tensile strength, elongation at break and oxygen permeability of nanocomposite with3%OMMT was increased22.16%,25.05%and22.6%respectively. Theoptical property was not distinct with the change of nanocomposite. The2%~4%addition of four boric acid sodium is determined through thewater resistant performance test.Finally, the Kraft paper and cardboard paper were coated by PVAcoatings, the results show that the barrier and properties of the coated paperare excellent, and the physical properties were improved...