Optimizing Physio-Mechanical Properties of Halloysite Reinforced Polyurethane Nanocomposites by Taguchi Approach

The vast and multi-oriented applications of pure TPU firmly stand in industrial and research fields. To further and deeper applications in these fields, TPU has been loaded as a host polymer with HNTs, in particular, to develop very well and attractive engineering materials that are commonly known as nanocomposites. In order to achieve the best results with minimum cost, Taguchi's approach was heavily used in labs as well as in industry. In this work, it is not only Taguchi analysis was used, but also ANOVA statistical approach to, further, fortify the analysis. Under the concept of using the two approaches, side-by-side, the results could be considered more reliable findings. Based on Taguchi approach, three levels for preparing TPU-HNTs nanocomposites were employed as follows: mixing temperature (190, 200, 210 degrees C); mixing speed (30, 40, 50 rpm); mixing time (20, 30, 40 min); and loading (1, 2, 3 wt.% HNTs). The controlled parameters and their three relevant levels were employed to test the response characterized by tensile strength, Young's modulus, and tensile strain. The most important results in this work were found to be loading TPU with only 1 wt.% HNTs which has improved the tensile strength and tensile strain by 44% and 144%, respectively. This improvement using the delicate parameters as chosen levels has outperformed all known results up-to-date. Surprisingly, however, the TPU crystal has shown very limited deformation as the field emission scanning electron microscope (FESEM) and thermogravimetric analyses (TGA) have suggested. The images at the fracture surface of TPU-HNT's samples taken by the FESEM have shown that the agglomeration could be the reason behind the insignificant effect of more HNTs loading.