Characterization and production of edible CMC film from sunflower stalk

This study consist of three stages including cellulose extraction from sunflower stalk, synthesis of carboxymethyl cellulose (CMC) from cellulose and preparation of CMC films. In the first stage, cellulose was extracted from sunflower stalk in the presence of alkaline. Next, cellulose was converted to CMC in the presence of alkaline with various weight ratio of sodium monochloro acetate (NaMCA) via alkalization and etherification reactions. After reaction yields were calculated, the relationship between NaMCA ratio and degree of substitution which is a sign for water solubility of synthesized CMC were investigated. In the final stage, film solutions were prepared by adding additives such as glycerin, polyethylene glycol (PEG) and citric acid (CA) to polymer solutions. Structural characterization and thermal stability of extracted cellulose, synthesized polymers and prepared films were investigated by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), respectively. Highest thermal stability was achieved with addition of glycerin and PEG to film solutions. The mechanical tests of the films were carried out by calculating tensile strength and elongation at break. Mechanical tests showed that glycerin as additive increases tensile strength at the films. Besides, water solubility, biodegradation behaviours and coating properties of all films are studied. As a conclusion, alternative CMC films were produced using sunflower stalk which is an organic waste as raw metarial. Keywords: Biodegradability, Carboxymethyl cellulose, Cellulose, Edible film.