Ultrasound-promoted preparation of cellulose acetate/organophilic clay bio-nanocomposites films by solvent casting method

Herein, we report the preparation of nanocomposites based on cellulose acetate (CA) and an organo-modified nanoclay, through a solvent blending method promoted by an ultrasound irradiation. The raw clay was modified by cation exchange (using sodium chloride then cetyltrimethylammonium bromide CTAB) aided by ultrasound, to expand the interlamellar spacing and facilitate the intercalation of the polymer. To improve the structural and thermal properties of the CA, several ratios of the organophilic clay (3%, 5%, 7% and 10%) were dispersed in the polymer matrix. The structural, morphological and thermal properties of nanocomposites were investigated by different analytical techniques such as X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning and transmission electronic microscopy (SEM and TEM). A successful intercalation of the CA in the nanoclay galleries was obtained for all the samples, in a short reaction time (1 h). Consequently, a substantial increase, of up to 50 °C in the thermal stability of the CA was obtained, when dispersing 7% of the organophilic clay. Graphical abstract