Mechanical and Physical Properties of Injection Molded Halloysite Nanotubes-Thermoplastic Polyurethane Nanocomposites

Abstract

The high aspect ratio of nanoscale reinforcements enhances the mechanical properties of pure polymer matrix. Researchers reported the mechanical properties of thermoplastic polyurethane and halloysite nanotubes (TPU-HNTs) nanocomposites formed through casting and compression molding. Few researchers reported on TPU-HNTs formed through injection molding. Therefore, the present work described the preparation, characterization, and processing of TPU and HNT nanocomposites via injection molding. TPU and HNTs were mixed using a brabender mixer with concentration ranging from 1wt.% to 7wt.% with varying mixing parameters (mixing speed, mixing time, and mixing temperature). Injection molding was used to form tensile bars shaped with varying molding parameters (injection temperature, injection time, and injection pressure). Significant increment of tensile strength was found at 1wt.%HNT loading concentration. The tensile strength of the TPU-HNT nanocomposite exhibited 24.29MPa at 1wt.% loading concentration, which was higher than that of pure TPU. The Young's modulus of the TPU-HNT nanocomposite was 15.45MPa at 7wt.%. Physical properties were analyzed using Thermogravimetric Analysis (TGA) and Field emission scanning electron microscopy (FESEM). FESEM results showed that HNTs were well dispersed in TPU matrix. TGA results showed that the addition of HNTs enhanced the thermal properties. Thus, TPU-HNT has improved mechanical and physical properties compared with pure TPU due to the addition of nanofiller.