Thermoplastic polyurethane synthesis with modified montmorillonite prepared by torque rheometry: Investigation of morphological, thermal, chemical, and physical properties

In this study, samples of thermoplastic polyurethane (TPU) were synthesized by reactive processing in an instrumented batch mixer with 0, 1, 2, 5, and 10 wt % of organophilic montmorillonite (OMMT) clay. Fourier transform infrared spectroscopy confirmed the obtainment of TPU. Transmission electron microscopy showed several types of clay dispersion. Analysis by X-ray diffraction revealed modifications in the TPU microstructure, a reduction in the degree of crystallinity, and an increase in the crystal size. Dynamic mechanical properties showed that the incorporation of OMMT has a strong influence on the storage and loss moduli obtained for the TPU matrix. The incorporation of OMMT also altered the crystallization and thermal stability of the TPU. With the use of the Flynn–Wall–Ozawa method it was observed that the nanoclay had a higher apparent activation energy. The results obtained applying the Criado method indicated that the solid state reaction is essentially controlled by geometric contraction, random nucleation with one nucleus for each individual particle and diffusion. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42640.