Characterization of PDMS-based magnetoelastomers via Rheometry
Sprache des Vortragstitels:
International Congress on Rheology
Sprache des Tagungstitel:
Magnetoelastomers are hybrid materials based on elastomers and magnetic particles. Because of their magnetic features, their mechanical properties and shape can be controlled by external magnetic fields. This effect occurs due to the magnetic particles which have been dispersed in the matrix. Concerning these externally induced changes, magnetoelastomers belong to the group of smart materials. These are substances which can react autonomously on a changing external environment. Different applications are possible, such as vibration reduction and change in the haptic properties. Additional applications might be possible, since their viscoelastic properties can be modified very fast by changing the external forces and also due to the variety of elastomeric matrices and filler particles.
Depending on the particle material and size, as well as their arrangement inside the cured elastomeric matrix, the obtained mechanical properties can be varied. Ultimately the movement of the particles is heavily dependent on the viscosity of the whole composite. Rheological measurements can provide such information, and additionally some information concerning the curing process. Depending on the different fillers used, different properties could be obtained, which again could be observed in the progress of curing.
During the first stages of this work, the preparation of the magnetoelastomeric material and corresponding rheological characterisation were carried out thoroughly. The isotropic materials consisted of a crosslinkable commercial polydimethylsiloxane matrix filled with different carbonyl-iron particles. These particles have different shapes and functionalities (coatings), which provide an insight into matrix-particle interactions at the interface and their impact on the final properties. In summary, the aim of this work is to study the crosslinking behaviour and its dependence on the particle characteristics by means of time resolved rheological measurements.