Synthesis and properties of magnetic sensitive shape memory Fe₃O₄/poly(ε‐caprolactone)‐polyurethane nanocomposites

Abstract

Fe 3 O 4 /poly (e-caprolactone)-polyurethane (PCLU) shape memory nanocomposites were prepared by an in situ polymerization method. The thermal properties, magnetic properties, and shape memory properties of the nanocomposites were investigated systematically. The results showed that the Fe 3 O 4 nanoparticles were homogeneously dispersed in the PCLU matrix, which ensured good shape memory properties of nanocomposites in both hot water and an alternating magnetic field (f ¼ 45 kHz, H ¼ 29.7 kA m À1 /36.7 kA m À1 ). The nanocomposites started to recover near 40 C, which is slightly higher than body temperature. Thus, they would not change their deformed shape during the implanting process into the human body. Considering potential clinical applications, 45 C was chosen as shape recovery temperature which is slightly higher than 37 C, and the nanocomposites had high shape recovery rate at this temperature. With increasing content of Fe 3 O 4 nanoparticles, the shape memory properties of the nanocomposites in an alternating magnetic field increased and the best recovery rate reached 97%, which proves that this kind of nanocomposites might be used as potential magnetic sensitive shape memory materials for biomedical applications.

Assessing magnetic nanoparticle aggregation in polymer melts by dynamic magnetic susceptibility measurements

“…Magnetic nanoparticles (MNPs) have been used as fillers in polymer nanocomposites in order to imbue the polymers with properties such as for electromagnetic interference shielding [33][34][35][36], for triggered drug release [37,38], and to enable magnetothermal repair of the damaged composite [39][40][41], among other applications [42][43][44][45]. For many of these applications it is ideal that the MNPs be well dispersed as single entities throughout the polymer matrix, such that their properties are predictable and such that their enhancement is uniform throughout the material.…”

Nanoscale Thermal Phenomena in the Vicinity of Magnetic Nanoparticles in Alternating Magnetic Fields

“…The ability of MNPs to dissipate heat in response to an applied magnetic field has become very useful for various applications, including cancer treatment [3] , magnetically triggered drug delivery [4] , and other applications outside of biomedicine, such as in driving chemical reactions [5] and repair of nanocomposites. [5b, 6] …”

Biodegradable magnetic‐sensitive shape memory poly(ɛ‐caprolactone)/Fe3O4 nanocomposites

“…The shape memory test in alternating magnetic field (SP‐15A Inductive Heating Machine, Shenzhen, China) were investigated according to the procedures reported by Cai et al . First, heat the samples to 60 °C for 1 min, then stretched to 200%, cooled to room temperature with an isothermal time of 1 min, unloaded external forces.…”