Degradation of Wax in Soil and Its Effect on the Nitrogen Release Behavior of Polyurethane Coated Urea. Issue 207 (3rd May 2020)

• Record Type: Journal Article
• Authors: Wu, Shu; Peng, Guirong; Yang, Yang; Ru, Tiejun; Wang, Jinming; Hong, Wei; Li, Qingshan
• Is Part Of: Integrated ferroelectrics. Issue 207(2020)
• Page Start: 243
• Page End: 255
• Publication Date: 2020-05-03
• Subjects: Controlled-release -- castor oil -- polyurethane coating -- alkyl -- degradation; Ferroelectric devices -- Periodicals; Integrated circuits -- Periodicals; 537.244805
• DOI: 10.1080/10584587.2020.1728684
• Languages: English
• ISSNs: 1058-4587

Abstract

Abstract: The polyurethane coated urea (PCU) was prepared by coating granular urea with the coating material, which was composed of castor oil, chain extender, polymeric MDI and wax. The wax as the sealant of the porous polyurethane coating was used to regulate the nitrogen (N) release rate of PCU. The test of N release behavior showed that the controlled-release effect of PCU in soil was inferior to that in water. Compare the analysis results of the PCUs in water, in alkaline water and in soil respectively, it showed that the structure of PU coatings was almost unchanged after immersion in water, and alkaline water, but after being buried in soil, the wax was degraded by microorganisms in the soil. The degradation of the wax changed the roughness and hydrophilicity of the coating. Calculation from IR demonstrated a loss trend of wax similar to the N release trends within 30 days, and the wax in the PU coating with 8 wt% wax degradated about 38 wt% after the coating was buried in soil for 40 days. The work shows that the stability of coating materials in water cannot prove his stability in soil. In order to make the PCU supply N slowly for a longer time in soil, wax or sealants with higher stability in soil should be selected and applied to the polyurethane coating.