The Effect of Calcium Carbonate, Rice, and Wheat Straw on the Biodegradability of Polyethylene/Starch Films

Abstract

A polyethylene (PE)/starch copolymer was prepared by a grafting technique in the presence of benzoyl peroxide as a catalyst and xylene as a solvent. The ratio of PE grafted onto starch was in ratio 1:5, respectively. The obtained grafted copolymer was characterized by Fourier transform infrared (FTIR) spectroscopy. The obtained grafted copolymer was mixed with rice and wheat straw as well as calcium carbonate (CaCO3) as a filler to form biodegradable films. Various analyses such as viscosity, tensile strength, elongation at break, water contact angle, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and solubility tests have been used to study the properties of biodegradable films in water and soil. CaCO3 and rice and wheat straws improved the biodegradability of the grafted copolymer. The presence of CaCO3 in the presence of rice and wheat straws increased the viscosity, tensile strength, thermal stability, and weight loss of the film in the soil. While elongation at break, the water contact angle and solubility in water decreased. According to the study, samples that were between 380°C and 400°C showed the highest polymer breakdown values and adding CaCO3 resulted in the lowest water contact angle.