Linear and non linear viscoelastic properties
Many liquids of great industrial importance have viscoelastic behavior. Some examples are: molten polymers, polymeric solutions, gels, suspensions and colloidal emulsions. The correct quantification of the viscoelastic behavior of the material is essential for the design of processes and products. it is done through different rheological tests, carried out mainly in rotational rheometers, but also in extensional rheometers and in experiments of flows in geometries similar to those of the processes of interest.
At GReo we have long experience in the rheological characterization of viscoelastic materials. Among the most important tests that we frequently perform, we can mention the small-amplitude oscillatory shear flow (SAOS) and the large-amplitude (LAOS) one. The SAOS tests provide the storage and loss modulus (G’ and G”), which are linear viscoelastic properties. LAOS tests provide non-linear viscoelastic properties, which are generally more relevant for industrial processes. GReo has recently developed and made available in the international scientific literature the most robust and at the same time the simplest analysis of LAOS test results. Our experience with viscoelastic materials also extends to several other tests that provide their properties.
Infrastructure: Seven modern rotational rheometers, equipped with the most varied accessories; CaBER extensional rheometer.