Effects of urea loading on soil biodegradation properties of melt‐processed polycaprolactone‐based composites for potential application in agriculture

Abstract

Herein, biodegradable composites of poly(ϵ-caprolactone) (PCL)/hydroxyapatite (HAP)/urea, with potential application in agriculture, were developed. The concentration of HAP was fixed at 3 wt%, while urea concentration varied from 1 to 9 wt%. The effects of urea loading on the morphological, flow properties, and soil biodegradation of PCL/HAP composites were investigated. The morphological characterization showed well dispersion of HAP and urea particles in the PCL matrix. A decrease in viscosity of PCL was noticed upon the inclusion of urea at 1 wt%, indicating the plasticization effects of urea, whereas an increase in viscosity was observed with increasing the concentration. The morphological analysis after soil burial showed microbial adherence on the surface of the samples. In addition, the formation of cracks, holes, and uneven surfaces were noticed. The atomic force microscope analysis showed an increase in surface roughness due to surface degradation of the samples. On the other hand, twostep degradation curves were noticed in the samples before soil degradation. In contrast, a single step degradation curve was observed after degradation, indicating the leaching of urea from the samples. Overall, PCL/HAP/urea composites with enhanced degradation rates were developed, and they can be applied in agriculture, where the materials can be buried after their end-use.