Authors: F. Chavarria and D.R. Paul
Affilation: The University of Texas at Austin and Texas Materials Institute, United States
Pages: 787 - 790
Keywords: thermoplastic polyurethane, nanocomposites
Thermoplastic polyurethane (TPU) nanocomposites were prepared by melt processing using a twin screw extruder. The effects of organoclay structure and hard segment concentration of the TPU matrix on mechanical properties and morphology of the nanocomposites were examined. Mechanical properties, transmission electron microscopy (TEM), and wide-angle x-ray diffraction (WAXD) data are reported. Specific comparisons of the structure of the organic treatment were made. The structural effects that produced the most significant enhancement in properties and morphology of TPU nanocomposites were the use of hydroxy-ethyl groups rather than methyl groups, one long alkyl tail instead of two, and a long alkyl tail in place of a short one. Higher degrees of exfoliation were obtained with a higher concentration of hard segments, as judged by TEM and WAXD. Although TPU is a polar matrix, some results show similar trends to polar, nylon 6 based nanocomposites while others follow the ones observed in non-polar matrices.