Rheological investigations of PDMS-based magnetolelastomers during curing
Sprache des Vortragstitels:
Annual European Rheology Conference
Sprache des Tagungstitel:
Magnetoelastomers are elastomeric-based composites whose mechanical properties and shape can be modified by means of external magnetic fields. This is accomplished by adding magnetic particles to an elastomer matrix, either in an isotropic or in an anisotropic arrangement, which respond to the application of the external magnetic field. These materials have increasingly been used as mechanical actuators or in applications involving controlled mechanical damping. The latter application is possible because the viscoelastic properties of the composite can be quickly adjusted in a controlled manner, by varying the magnetic field direction and strength.
The final mechanical properties applications of magnetoelastomers have a strong dependence on the particle distribution and their arrangement within the elastomeric matrix. The required movement of the particles inside the matrix depends obviously to a great extent on the viscosity of the system before it cures completely. In order to properly control these parameters, knowledge about the rheological properties of the composite system is therefore essential.
This work deals with the preparation and rheological characterization of isotropic magnetoelastomers based on a commercial polydimethylsiloxane (PDMS) matrix filled with carbonyl iron particles. Various particle shapes and surface functionalities of the particles are used with the purpose of trying to achieve customised interactions at the matrix-particle interface. The initial approach consists on studying the crosslinking kinetics and its dependence on the particle properties by means of time-resolved rheological measurements. This information will be important for further experimental and computational work. Preliminary results of the dynamic mechanical properties of the first isotropic specimens will be also briefly discussed, both with and without a magnetic field being applied during mechanical testing.