Effect of hydrochloric acid on the properties of biodegradable packaging materials of carboxymethylcellulose/poly(vinyl alcohol) blends

The main focus of this research was to prepare ecofriendly biodegradable packaging materials with carboxymethylcellulose (CMC) and poly(vinyl alcohol) (PVA). Different blend films were prepared through the variation of the ratios of CMC to PVA (00:100, 30:70, 50:50, 70:30, 100:00 w/w) with and without hydrochloric acid. The mechanical properties, including the tensile strength (TS), percentage elongation at break (Eb), water uptake, and solubility in water, of the films were investigated. A soil burial test was also performed. The prepared films were characterized by attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The highest TS and Eb values of the blend films were recorded as 19.52 MPa and 34.52%, respectively. ATR-FTIR spectroscopy, DSC, and TGA results provided that in the presence of HCl, a chemical reaction occurred between CMC and PVA. In addition, the water uptake, solubility in water, and biodegradability of the films were found to be reduced significantly. With all of these results, in presence of HCl, a blend made up of CMC and PVA with a ratio 30:70 was optimized as a biodegradable packaging material. (C) 2015 Wiley Periodicals, Inc.