Identification of strain-Induced Thermal Response in polymer melts and liquid glass formers

We are working on improving the way to characterize liquids and viscoelastic fluids by reinforcing the fluid/substrate interfacial forces (total wetting) and building the temperature cartography upon applying an oscillatory mechanical shear field. Three fluids are studied: a low molecular weight polybutylacrylate (PBuA), the polypropyleneglycol (PPG) and the glycerol. We demonstrate that the fluids do not dissipate the injected strain energy but transforms it in shear bands of opposite temperature variations synchronous with the applied shear field. This thermodynamic change suggests a coupling to shear elastic modes in agreement with the identification of low frequency shear elasticity theoretically foreseen and experimentally demonstrated