Xylan-starch-based bioplastic formulation and xylan influence on the physicochemical and biodegradability properties

Abstract

As the traditionally used plastic remains and accumulates in the environment, new biodegradable materials and, preferably, from renewable raw materials, need to be developed. In this regard, this study investigates the influence of xylan from sugarcane bagasse on the mechanical and chemical properties of bioplastics composed of starch and glycerol as a plasticizer. All bioplastics produced have a total proportion of sugars equal to 5% (w/w total mass of the filmogenic solution), and xylan is present in 5, 10, 25, and 50% of the total mass of polysaccharides. Bioplastic-forming solutions were gelatinized and dried by the casting method. Bioplastic solubility in water and its opacity increase as the xylan content increases—the first range between 20.31 and 44.16%, and the latter between 0.44 and 9.77%, with only starch and 50% (w/w) xylan, respectively. The presence of xylan also makes the bioplastics more hydrophilic and less crystalline, and interferes with their mechanical proprieties, while 5 and 10% (w/w) xylan bioplastics have higher tensile stresses, equal to 2.35 and 2.56 MPa, respectively. The elongation at break is greater in bioplastics composed of only starch (208.8%), and 15.8 and 19.3% elongation is reached to the amount of xylan of 25 and 50%, respectively. The bioplastics are completely biodegraded after being buried for 30 days. Starch and xylan (5 and 10%) combination improves the mechanical properties of the film, causing no significant changes in its solubility and producing biodegradable and less opaque bioplastics, with potential application in packaging for transporting seedlings, for example.