Polylactide/cellulose acetate biocomposites as potential coating membranes for controlled and slow nutrients release from water-soluble fertilizers

The unbalanced release of fertilizers influences the availability of nutrients in soil, and their leaching affects the ground water sources. Therefore, the coating of water-soluble fertilizers is considered as the main approach that improves their uses. Here, biodegradable coating based on polylactic acid (PLA) and cellulose acetate (CA) was proposed for the first time to encapsulate diammonium phosphate (DAP) granules using a rotary pan. The blends were prepared by vigorous mixing of PLA and CA in a solvent mixture using a homogenizer equipment and the prepared films of homopolymers and their blends were fully characterized (IR, DSC, TGA, SEM, EDS). Moreover, the coating thicknesses were controlled by adjusting the duration of the coating process. The delaying performance of the coatings meet the release rate required by the European standard (20 % of P released in the first 24 h). The introduction of CA decreases the PLA crystallinity and therefore accelerates the degradation of the coating in soil.