Temperature effect on thermal, mechanical, and electrical properties of Ag nanoparticle filled thermoplastic polyurethane composites

Ag nanoparticle filled thermoplastic polyurethane (AgNPs/TPU) composites are widely used in medical, energy, packaging, electronic devices, additive manufacturing and many other fields, where the service temperature fluctuates easily, making it necessary to study the temperature effect on the properties of composites. In this work, multifunctional AgNPs/TPU composites with different AgNP contents were prepared by a mixing and hot-pressing method. The results show that the phase change property of TPU is not affected by the addition of AgNPs, but the thermal diffusivity is improved. As the content of AgNPs increases, the thermal conductivities of AgNPs/TPU composites increase significantly, whereas the temperature has an opposite effect. The results of elongation at break and tensile strength show a decreased trend with the increase in the AgNP content and a trend of first increasing and then decreasing with the increase in temperature. As the temperature increases, the tensile moduli of AgNPs/TPU composites decrease significantly. For the temperature higher than 50 degrees C, the electrical percolation thresholds of composites decrease from 5.5 vol% to a lower content. The results prove that the temperature has a significant influence on the thermal, mechanical, and electrical properties of AgNPs/TPU composites.