Traditional nitrogen fertilizers, such as urea, are inefficient and harmful to the environment due to runoff, nitrate leaching, ammonia volatilization, and nitrous oxide emissions. Current controlled-release nitrogen fertilizers that utilize polymer-coated urea granules (PCUs) demonstrate excellent controlled-release properties, increasing fertilizer efficiency. However, the high cost and poor biodegradability of PCUs limits their commercialization. Introducing hydrogen bonding moieties (e.g. urea) results in high mechanical strength, while promoting biodegradability. Melt polymerization of polyureas, without the use of isocyanates, is economical and afforded high molecular weight polymers that are semi-crystalline and optically transparent. Incorporation of biosourced monomers into polyureas increased biocompatibility without compromising on mechanical properties. Various analytical techniques including TGA, DMA, and DSC identified these polyureas as tough thermoplastics, and compression molding provided insight into melt processability. Finally, the use of biosourced polyureas as fertilizers capitalizes on natural soil enzymes which readily hydrolyze polyureas to yield a feedstock of nitrogen.

Synthesis and characterization of isocyanate-free polyureas

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.