Shape memory effect of poly(d,l-lactide)/Fe3O4 nanocomposites by inductive heating of magnetite particles

In this paper, the preparation of biocompatible poly(d,l-lactide) (PDLLA)/magnetite (Fe3O4) nanocomposites and their shape memory effect are reported. Fe3O4 nanoparticles with an average size of 20 nm were synthesized by chemical co-precipitation and mixed uniformly with a PDLLA matrix. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and mechanical testing were carried out to determine the micro-surface morphology, glass transition temperature (Tg), functional groups change and mechanical properties of the PDLLA/Fe3O4 nanocomposites. The interesting shape memory behavior of the nanocomposites induced by an ultrasonic alternating magnetic field were also observed. SEM and DSC showed that there was a close interaction between the polymer matrix and the magnetic nanoparticles. Formation of weak hydrogen bonds between the CO in PDLLA and Fe–OH groups of the surface of nano-crystalline Fe3O4 was examined by FTIR. The PDLLA/Fe3O4 nanocomposites displayed a desirable shape memory effect.