Preparation and properties of cellulose-based nano composites of clay and polypropylene

Composites of polypropylene (PP) and crystalline cellulose were prepared after modification of the host matrix by reactive extrusion grafting of maleic anhydride. Acid, alkali, and mechanical treatment of wood flour (WF) was conducted to obtain a suspension of micro- and nanocrystalline cellulose. Layered silicates (clay) were partially intercalated with cellulose crystals, and the modified layered silicate was used as filler in the PP matrix at various concentrations via a melt-blending process. The tensile strength of composites prepared from cellulose-modified clay was greater than that of the PP-clay and PP-WF composites at a 5% filler concentration, whereas deterioration of mechanical properties was observed when clay and WF were used alone for reinforcement. The dispersion of the filler in the matrix significantly decreased after clay modification with cellulose at higher concentrations, as shown by X-ray diffraction (XRD) data and transmission electron microscopy (TEM) images. Thermogravimetric analysis (TGA) showed an increase in the thermal resistance of samples, which was attributed to the presence of clay platelets that dissipated heat by generating torture paths. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012