Thermomechanical behaviours of unfilled/filled thermoplastic polyurethane

Thermoplastic polyurethane (TPU) exhibits enormous mechanical performance and extensibility in both engineering, industry and scientific applications. The filled polymer which enclosed rigid particles has mainly improved on mechanical properties. The work focused on three TPUs, carbon-black-filled TPU, supramolecular TPU, and sugar-filled TPU. To characterise their advantages and fundamental properties, thermo-mechanical analysis, mechanical experiments and scattering techniques can be used. However, testing rubber material in high rate responses is difficult. Therefore a principle of time-temperature superposition was employed to associated mechanical behaviour with temperature and loading rates. The principle was as foundation connecting all experiments and modelling procedures to cooperate the thermo-mechanical data with linear viscoelastic theory. Upon this methodology, these behaviours in TPU and its composites can be calibrated, further predicted on high strain rates. The study of the interpretation of the phenomenological model is not only responsible for reproducing strain-stress behaviour from low- to high-strain rates, but also take advantage of time-temperature equivalence on thermo-mechanical behaviour for objectives linking between different conventional experiments. The purpose of the research is to characterise mechanical behaviour on different types of TPU materials, explore their properties especially in high strain rates, at last develop the application of viscoelastic theory in order to describe polymer at large deformation in high rate experiments.