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 [Zn0.64·Al0.36·(OH)2]Cl0.36·nH2O, 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.