Preparation and properties of layered double hydroxide-carboxymethylcellulose sodium/glycerol plasticized starch nanocomposites

The Zn-Al layered double hydroxide (LDH) was fabricated using carboxymethyl-cellulose sodium (CMC) as the stabilizer in aqueous solution, and then used as the filler to prepare LDH-CMC/glycerol plasticized-starch (GPS) nanocomposites in the casting process. Transmission electron microscopy exhibited the platelets of LDH-CMC with a lateral size of 30-60 nm and the thickness of 5-10 nm. X-ray diffraction showed that the presence of CMC decreased the thickness of LDH. The chemical formulas of LDH was [Zn(0.64).Al(0.36)center dot(OH)(2)]Cl(0.36)center dot nH(2)O, and the content of CMC was about 37.5 wt%. LDH-CMC possessed the good stability in water because of hydrophilic CMC components and the smaller size of each LDH stack. A low loading of LDH-CMC (below 6 wt%) could obviously improve mechanical properties and water vapor barrier of the nanocomposites, because LDH-CMC could form the good interaction with GPS matrix. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.