Green nanocomposites based on thermoplastic starch and steam exploded cellulose nanofibrils from wheat straw

The objective was to characterize the properties of cellulose nanofibril/TPS based nanocomposites. The cellulose nanofibrils were extracted from wheat straw using steam explosion, acidic treatment and high shear mechanical treatment. These nanofibrils were dispersed in thermo plastic starch (TPS) using a Fluko high shear mixer in varying proportions and films were casted out of these nanocomposites. The cellulose nanofibrils were characterized using AFM, TEM, SEM, TGA, FUR and WAXRD and the nanocomposite films were analyzed in terms of SEM, WAXRD, TGA, DSC, mechanical and barrier properties. XRD and TGA results confirmed the crystalline nature of nanofibrils. AFM and TEM images revealed fiber diameter in the range 30-70 nm. TGA depicted an increasing in residue left with increase in cellulose nanofibrils content. Mechanical properties increased with nanofiber concentration. Barrier properties also improved with addition of nanofillers up to 10% but further addition deteriorated properties due to possible fiber agglomeration. (C) 2010 Elsevier Ltd. All rights reserved.