Mechanical properties of soil buried kenaf fibre reinforced thermoplastic polyurethane composites

•We developed composites from kenaf and thermoplastic polyurethane.•Soil burial of composites after 80 days shows increase in flexural strength.•Soil burial of composites after 80 days shows increase in flexural modulus.•Tensile properties of composites degrade after soil burial tests.•We investigate the morphological fracture through scanning electron microscopy.

A study on mechanical properties of soil buried kenaf fibre reinforced thermoplastic polyurethane (TPU) composites is presented in this paper. Kenaf bast fibre reinforced TPU composites were prepared via melt-mixing method using Haake Polydrive R600 internal mixer. The composites with 30% fibre loading were prepared based on some important parameters; i.e. 190 °C for reaction temperature, 11 min for reaction time and 400 rpm for rotating speed. The composites were subjected to soil burial tests where the purpose of these tests was to study the effect of moisture absorption on the mechanical properties of the composites. Tensile and flexural properties of the composites were determined before and after the soil burial tests for 20, 40, 60 and 80 days. The percentages of both moisture uptake and weight gain after soil burial