Cellulose Esters From Birch Kraft Pulps - New Biomaterials For Barrier Coating

In the present study cellulose fatty acid esters were synthesized and characterized from chemical pulps, with different hemicellulose contents. We proceeded then to prepare and characterize paperboard coatings based on these materials. The cellulose esters obtained were characterized by FTIR and P-31 NMR. The degree of substitution was found to increase from 0.8 to 2.8, with increasing fatty acid chloride stoichometry. The coatings were clearly hydrophobic and the bather properties importantly were found not to vary significantly at all between the cellulose substituents and the degrees of substitution. Water contact angle values were over 90 degrees. Hydrophobicity was also confirmed by low water absorption into the coated boards; the values being similar to those of commercial ones. The best water vapor bather properties, i.e. the lowest water vapor transmission rates (WVTR) were obtained for the coatings prepared from the palmitoyl esters of the low hemicellulose content pulp cellulose. This compound was comparable to those of commercial PE- and PLA-coated boards. The cellulose ester coated boards were also good oil and grease bathers.