Effect of nano-biochar on mechanical, barrier and mulching properties of 3D printed thermoplastic polyurethane film

In this research work, the nano-biochar/thermoplastic polyurethane (TPU) nanocomposite mulching films were successfully prepared by fused deposition modelling (FDM) process. The biochar was prepared by pyrolysis of digitalis purpurea plant at 400 celcius and the size of biochar was reduced to 80 nm by ball mill method. Various concentrations (0, 2, 4, 6, 8, 10 wt%) of nano-biochar was blended with TPU and the extrusion filament was prepared. The FDM printer was used for the preparation of single-layer mulching films with the thickness of 0.4 mm. The addition of various concentrations of nano-biochar increased the surface colour difference from 14.48 to 63.07 and decreased the light transmittance from 82 to 21%. The hydrophobic properties of nanocomposite mulching films were increased by the incorporation of nano-biochar and the highest value of 116 degrees was achieved for 10 wt% of nano-biochar. The porosity of the films was decreased from 0.7 to 0.2% and the water absorption was increased from 0.1 to 0.43% for 48 h. The tensile and tear strength of the films were increased to 38 MPa and 4.1 MPa. The maximum penetration and impact resistance of 26.7 N and 279 g was achieved for 10 wt% of nano-biochar. The burst strength was increased from 78.2 to 94.5 kPa. The OTR and WVTR was decreased from 1765.45 to 1011.34 cc/m(2) day.atm and 19.4 to 11.9 g/m(2) day. The lowest frictional coefficient of 0.3 and minimum soil temperature was attained for 10 wt% of nano-biochar.

Automated summary

In this research, nano-biochar/thermoplastic polyurethane nanocomposite mulching films were successfully prepared by fused deposition modelling process. The addition of nano-biochar improved the color, light transmittance, hydrophobicity, and mechanical properties of the mulching films.