Coating of urea granules by in situ polymerization in fluidized bed reactors

Abstract

ObstractThe main objective of the present work is to produce and characterize urea granules coated with polymers prepared with aqueous solutions of acrylic acid and glycerol. Both coating and drying of urea granules were performed in a fluidized bed reactor. Fourier transform infrared spectroscopy analyses indicated the presence of poly(acrylic acid) and acrylic acid / glycerol copolymers on the granule coating and the formation of chemical bonds between urea and the polymer coating. Scanning electron microscopy images showed that the original and coated urea granules presented different characteristics, reinforcing the idea that coating occurs in the fluidized bed. Finally, rates of urea release showed that the coated granules presented slightly slower rates of urea dissolution in water due to the presence of the coating layer. Therefore, it is shown that it is possible to produce coated urea granules through in-situ polymerization onto the granule surface using a fluidized bed.

Thermal, Morphological and Mechanical Properties of Multifunctional Composites Based on Biodegradable Polymers/Bentonite Clay: A Review

“…The in-situ polymerization method can be used to fabricate product based on polymer nanocomposites to be applied in several applications such as coatings [ 46 ], adhesives [ 47 ], sealants [ 48 ], etc. The method’s main advantage is greater control over reaction conditions, such as temperature, concentration, and reaction time, which can lead to more consistent and controlled properties in the polymers produced [ 49 ].…”

Microfluidic encapsulation for controlled release and its potential for nanofertilisers

“…109,110 In some cases, the difference in whether the copolymerization happens before or simultaneously with the coating process can lead to a change in coating properties, as shown in Figure 4. 111 Some other parameters can also affect the quality of the coated fertilisers produced using this approach. The coating thickness depends on the size of the granules and the viscosity of the coating solution.…”

Biopolímero: efeitos em aspectos físico-hídricos do solo e na dinâmica de nitrogênio e potássio

“…De maneira geral, em toda a cadeia agrícola, a aplicação de polímeros pode ser realizada na forma de aditivos, revestimentos de sementes, imersões de raízes e assim por diante (Zohuriaan-Mehr e Kabiri, 2008), como o polímero pode aliviar o ônus da escassez de água, o uso adequado está em áreas áridas e semiáridas (Bakass et al, 2002;Zohuriaan-Mehr e Kabiri, 2008;Han et al, 2010), tendo efeito positivo na retenção de água em vários tipos de solos, podendo melhorar as propriedades físicas e químicas do solo, com vistas a aumentar sua capacidade de retenção de água e retenção de nutrientes no solo, atrasar o tempo para atingir o ponto de murcha permanente, prolongar a sobrevivência das plantas sob estresse hídrico (Viero et al, 2002;Abedi-Koupai e Asadkazemi, 2006;Orikiriza et al, 2009;Fernandes et al, 2019).…”