Innovative Hydrogels Made from Babassu Mesocarp for Technological Application in Agriculture

The controlled release of macronutrients via hydrogels using biopolymers is a solution for agricultural production. Two superabsorbent hydrogels (SAH) were synthesized by the graft copolymerization reaction of babassu mesocarp (MB) and polyacrylamide (PAM). Both were distinguished by the presence (HMBP) or absence (HMB) of potassium phosphate fertilizer, which can be used as nutrient carriers and soil's conditions correctives as well. These materials were characterized by X-ray diffraction (XRD). The hydrogels presented crystallographic characteristics different from their precursors, which indicated interactions among the fertilizers and macromolecular chains. Through Fourier transform infrared spectroscopy (FTIR), a band at 1,121 cm(-1) differentiates the HMBP and HMB hydrogels and was attributed to the incorporation of potassium phosphate. Thermogravimetric analyzes (TG and DTG) showed the thermal stability of the obtained materials. The swelling tests showed a superabsorbent capacity of the materials since they had swelling capacity ranging from 250 to 300 (g/g) at the expense of the pH of the medium. Regarding the toxicity of these materials, a study using Artemia showed that the developed products do not present risks. Furthermore, hydrogels containing potassium phosphate have great potential to control macronutrient delivery systems. Therefore, they are a promising input as soil conditioners and nutrient carriers for agricultural applications.