Preparation and properties of poly(acrylic acid-co-styrene)/Fe3O4 nanocomposites

Poly(acrylic acid-co-styrene)/Fe3O4 nanocomposites were prepared using poly(acrylic acid-co-styrene) (P(AA-co-St)) and nano-Fe3O4 particles. The resultant materials were characterized by transmission electron microscope (TEM), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), advanced rheology expand system and superconducting quantum interference device (SQUID) magnetometer. The diameter of the magnetic particles was around 3-14 nm. The experimental results reveal that the acrylic acid segment of P(AA-co-St) can react with nano-Fe3O4. With increasing reaction time the storage modulus, loss modulus, complex viscosity and shear stress of the P(AA-co-St)/Fe3O4 ethanol suspension were increased, and the suspension changed from liquid-like behavior to gel-like behavior for the reaction between P(AA-co-St) and Fe3O4, as found during the rheology measurements. The thermal stability of P(AA-co-St) decreased with the addition of nano-Fe3O4, and the nanocomposites exhibited superparamagnetic properties above the blocking temperature.