Application of graphene-oxide-modified polyacrylate polymer for controlled-release coated urea

Abstract

Polyacrylate polymer (PA) was modified with graphene oxide (GO) and the obtained composites were applied as coatings for controlled-release coated urea (CRU). The physicochemical properties of the different PA/GO coatings were characterized in detail and the nitrogen-release characteristics of the obtained CRU samples were determined in water at 25 °C. The experimental results revealed that addition of GO to PA reduced the swelling degree from 83.01% to 46.35% and improved its mechanical properties (the Young's modulus was improved from 31.52 to 34.97 MPa and the glass transition temperature was increased from 4.21 to 6.11 °C), thus dramatically slowing down the cumulative nutrient release from the CRU fertilizer from 87.25% to 59.71%. These results suggest that GO enhances the properties of PA for CRU applications, which shows that GO-modified PA is a good coating material.