Shape-memory behavior of magnetic bionanocomposites

CALVO CORREAS, TAMARA; MEIORIN, C.; DÍEZ, I.; CORCUERA, M.A.; ECEIZA, A.

San Sebastian

Simposio; 24° International Symposium on metastable, amorphous and nanostructured materials (ISMANAM 2017; 2017

In the last decades, the interest in the development of shape-memory polymers (SMPs) has increased considerably among smart materials, since they find applications in different fields [1]. These kind of smart materials stand out due to their ability to remember their original shape after being deformed and recover it as a response to an external stimulus [2]. Among SMPs segmented polyurethanes (STPUs) are one of the most noteworthy, due to their versatility, which enables the synthesis of materials with different properties just by manipulating their composition. STPUs are block copolymers composed by two blocks, one formed by a macrodiol and the other composed by a diisocyanate and a low molecular weight chain extender.Furthermore, the demand for the design of polyurethanes derived from renewable sources has increased due to economical, environmental and social concerns. Therefore, the use of biobased macrodiols and chain extenders is increasing in the synthesis of polyurethanes [2,3]. Moreover, although the most employed diisocyanates are derived from petroleum, it is noteworthy the increased use of biobased diisocyanates, being L-lysine diisocyanate, which is derived from L-lysine amino acid, one of the most studied [2]. In addition, shape-memory properties of polyurethanes can be can be enhanced by loading different nanoentities. Moreover, the addition of magnetic nanoparticles allows the possibility of activate shape recovery by applying a magnetic field [4]. In this context, shape-memory bionanocomposites with magnetic properties (Figure 1) based on a fully biobased polyurethane synthesized from a castor oil based macrodiol, L-lysine diisocyanate and biobased 1,3-propanediol and with different magnetite nanoparticles (MNP) contents, and also with a combination of MNP and CNC have been prepared by solvent-casting. The effect of content of the nanoentities in thermal, morphological, mechanical and shape-memory properties has been investigated.