INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Shape Memory Polymers Based on Epoxy Matrices modified with Oleic Acid and Magnetic Nanoparticles
Autor/es:
J. PUIG; C.E. HOPPE; L.A.FASCE; C.J. PÉREZ; R.J.J. WILLIAMS
Lugar:
Lyon
Reunión:
Simposio; 2nd International Symposium in Frontiers in Polymer Science; 2011
Resumen:
Shape memory polymers (SMPs) are smart materials used for the design of actuators with useful applications in several fields (biomedicine, sensing, robotics, etc). These materials have the ability to return to its original shape from a deformed intermediate shape by applying an external stimulus (temperature, magnetic or electrical field, light, pH, etc.). Interest in SMPs is based on their lower cost, greater versatility in operating temperatures, higher breaking strains (and stresses), and improved strain fixing and recovery compared to those based on metal alloys (SMAs, shape memory alloys). Epoxy networks have excellent mechanical properties, but only in a few recent works have been proposed as SMPs. The activation temperature of these materials is the glass transition temperature, which can be modulated by changing the formulation and/or curing cycle of the reactive system.1-3 However, their use as SMP requires excellent mechanical properties in the rubbery state (high breaking strain, good strain recovery, good toughness), not always easy to achieve with this type of polymers.2 The application of an external magnetic field to a SMP that has incorporated magnetic particles produces a inductive heating that can achieve remote actuation.4-8 In this work epoxies networks based on the homopolymerization of an epoxy monomer in presence of different amounts of a fatty acid are obtained. Oleic acid (OA) was reacted with DGEBA (E) in the presence of a tertiary amine (BDMA) to give products whose thermal and mechanical properties were controlled by the molar ratio of epoxy (E) to carboxyl groups (E/OA). The glass transition temperature of the resulting network could be varied as a function of the amount of OA. The incorporation of oleic acid-coated magnetite nanoparticles (NPs) to these networks is expected to produce the activation of the shape memory effect in the presence of an alternating magnetic field. Different formulations and their compatibility with magnetite NPs are investigated to obtain products with good shape memory properties and remote actuation by a magnetic field.