Bio-based superhydrophobic polymer coatings for slow-release fertilizers via a UV-curing encapsulation method

In this study, a solvent-free UV-curing roller coating technology was developed to prepare bio-based superhydrophobic polymer coatings for slow-release fertilizers. In detail, acrylate epoxidized soybean oil monomer was cured under UV irradiation with Mg(OH)2 modified with stearic acid followed by immobilized with paraffin wax as the hydrophobic fillers. The microstructure, thermal stability, surface hydrophobicity of the resulting composite coatings and the release properties of the coating fertilizers as well as its effect on the actual growth of corns were analyzed systematically. The results showed that under UV irradiation for 30–60 s; the poly-epoxidized soybean oil acrylate (PESOA) coating modified by stearic acid @ Mg(OH)2 and paraffin wax demonstrated good hydrophobicity with the contact angle of 150.4° ± 1.25°. When the coating content reached about 7 %, the initial release rate was only 1.625 % and the N release longevity reached high to 63 days. This UV-curing method provides a new and simple strategy for the preparation of cost-effective bio-based slow-release fertilizers.