Morphology and tensile properties of thermoplastic polyurethane-halloysite nanotube nanocomposites

Abstract

The high aspect ratio of nanoscale reinforcements enhances the tensile properties of a pure polymer matrix. Researchers have reported the morphology and tensile properties of thermoplastic polyurethane and halloysite nanotube (TPU-HNTs) nanocomposites, formed through compression moulding processes. Few researchers have reported on TPU-HNTs formed through injection moulding. Therefore, the present work investigates the tensile properties of TPU and HNT nanocomposites via injection moulding. TPU and HNTs were mixed using a brabender mixer with concentrations ranging from 1wt.% to 15wt.% and varying mixing parameters (i.e., mixing speed, mixing time, and mixing temperature). Tensile bars were injection moulded by varying the moulding parameters (i.e., injection temperature, injection time, and injection pressure). A significant increment of tensile strength was found at 1wt.% HNT reinforcement. TPU-HNT nanocomposite with 1wt.% reinforcement exhibited tensile strength of 24.3 MPa, which was higher than that of pure TPU. The Young's modulus of the TPU-15wt.% HNT nanocomposite was 21.5 MPa. Thus, TPU-HNT had improved mechanical properties, compared to pure TPU, due to the addition of a nanofiller.