Biodegradable magnetic-sensitive shape memory poly(ε-caprolactone)/Fe3O4 nanocomposites

A novel biodegradable magnetic-sensitive shape memory poly(epsilon-caprolactone) nanocomposites, which were crosslinked with functionalized Fe3O4 magnetic nanoparticles (MNPs), were synthesized via in situ polymerization method. Fe3O4 MNPs pretreated with gamma-(methacryloyloxy) propyl trimethoxy silane (KH570) were used as crosslinking agents. Because of the crosslinking of functionalized Fe3O4 MNPs with poly(epsilon-caprolactone) prepolymer, the properties of the nanocomposites with different content of functionalized Fe3O4 MNPs, especially the mechanical properties, were significantly improved. The nanocomposites also showed excellent shape memory properties in both 60 degrees C hot water and alternating magnetic field (f=60, 90 kHz, H=38.7, 59.8 kAm(-1)). In hot water bath, all the samples had shape recovery rate (R-r) higher than 98% and shape fixed rate (R-f) nearly 100%. In alternating magnetic field, the R-r of composites was over 85% with the highest at 95.3%. In addition, the nanocomposites also have good biodegradability. (C) 2017 Wiley Periodicals, Inc.