Synthesis and characterisation of biodegradable polyurethane/CuS nanocomposites for agricultural application

Polyurethane (PU) is one of the important industrial polymers. PU and its composites can be used in different applications. This paper examines the potential of PU/copper sulphide (CuS) nanocomposites (NCs) for application as green mulching films in agriculture. Castor oil-based PU NCs were fabricated by varying the CuS concentration viz., 0.0%, 1.0%, 2.0%, 4.0% and 8.0%. The NCs were characterised for microcrystalline nature by X-ray diffraction, Fourier transform infrared spectroscopy used for examining spectral characteristics, morphological assessment by scanning electron microscopy and elemental analysis by energy-dispersive x-ray Spectroscopy. The NCs were characterised for tensile properties, which revealed that a 4% PU/CuS nanocomposite (NC) exhibited high elongation at break of 399.72 MPa, suitable for mulching applications. Thermogravimetric analysis was used to examine the thermal stability and degradation. The chemical resistance and water absorption were evaluated in various atmosphere. The biodegradability was investigated through the soil and cow dung burial test. The pot study experiment is conducted to investigate the effect of NC on growth rate of the plants, which showed that beans treated with PU/CuS NC showed a 43% increase in height within 7 days and a 32% increase within 35 days, with an increase of about 62.5% in leaf width within 7 days and continues to increase until the 35th day and shows considerably more branches and stem diameter than the control. This work concludes that PU/CuS NCs have high potential as green mulching films for application in agriculture.

Graphical abstract