Enhancement of biomaterials based on starch for protection of agricultural soils

HÉCTOR ALEJANDRO ANZORENA; MARIO D. NINAGO; LÓPEZ, OLIVIA VALERIA

Buenos Aires

Congreso; XI World Chemical Engineering Congress; 2023

XI World Chemical Engineering Congress

Recent technological advances in agricultural fields, motivated by the raising necessity of providing higher quantities of food as a consequence of the world’s population growth, have led scientists to look into technologies that widen control over variables that affect crops’ yield, including crops in protected environments, underground irrigation systems and the use of agricultural mulches. Materials used for mulching are mainly from petrochemical source due to their high production, low cost, and easy processing. However, their major drawback is their non-biodegradability, so they end up accumulating and causing irreversible environmental damage. The use of biodegradable films, produced from biopolymers such as starch, is being widely studied as a promising alternative, making use of these biopolymers’ film forming capacity, besides their global abundance and their inherent biodegradability [1]. In this work, biodegradable films were obtained from cassava starch suspensions at 5 % w/v, bentonite clay, acting as a filler (matrix reinforcement), was added up to 10 % w/w, and sodium borate, acting as a crosslinking agent, was added up to 3% w/w. Formulations were gelatinized at 90 ºC for 20 minutes and subsequently poured into acrylic molds maintaining a constant mass:area ratio, then they were dried at 60 ºC for the next 24 h and conditioned at 65 % RH until testing. Microstructure and UV-vis barrier capacity of films were determined by infrared spectroscopy and absorption spectrometry. Whereas dimensional stability and mechanical properties were evaluated by tensile tests, water solubility, and composting capacity. Obtained results showed that the incorporation of mineral particles reinforced the starch matrix, boosting its mechanical properties and increasing its radiation barrier capacity up to 6,6 times, compared to the unfilled matrix. Moreover, the presence of crosslinking agent improved the overall appearance of the films and reduced by 10,9 % the mass loss after 90 days of composting