Ring oxpening polymerization of D,L-lactide on magnetite nanoparticles

The ring-opening polymerization of D,L-lactide initiated by tin(II) 2-ethylhexanoate (Sn(Oct)(2)) on the surface-initiated magnetite (Fe3O4) nanoparticles was performed at 130 degrees C. The effects of the polymer molar mass and concentration oil the amount of surface polymer were investigated. The number average molecular weights, M-n obtained by both NMR and GPC methods fit well within the accuracy of the applied methods and ranged from 1, 100 to 4,040 g . mol(-1). A Surface functionalization density of up to 625 initiation sites per particle was obtained. The composition of various core-shell particles was determined by TGA, with results indicating magnetite (Fe3O4) Contents, mu(m), between 17 and 59 wt%. Under the influence of a magnetic field, the heating generated by superparamagnetic core-shell particles suspended in toluene presented guidelines for an optimization of magnetic particle systems with respect to an application for hyperthermia.