Characterization of the hydrogen bond in polyurethane/attapulgite nanocomposites

In this article, thermoplastic polyurethane (TPU)/attapulgite (AT) nanocomposites were prepared by solution blending. The interaction between AT and TPU was investigated by Fourier transform infrared (FTIR) and dynamic mechanical analysis (DMA). The carbonyl stretching region (1680-1760 cm(-1)) of infrared spectra was studied to investigate the difference of the hydrogen bonding degree of the samples. The degree of hydrogen-bonded carbonyl groups of the samples were found to be increased with increasing AT content and decreased with increasing temperature. The equilibrium between free and hydrogen-bonded carbonyl groups was discussed. The values of dissociation enthalpy of the hydrogen-bonded carbonyl groups increased with increasing AT content. Quantitative evaluations of the interaction between AT and TPU was conducted by analyzing the physical cross-links density of the samples. The results indicated that the physical cross-links density of the samples increased with increasing AT content. The results of tensile tests showed that with increasing AT content, the mechanical properties of the samples increased, which confirmed that strong interaction was formed between AT and TPU matrix. (C) 2015 Wiley Periodicals, Inc.