writer：X. Yan, Q. He, X. Zhang, H. Gu, H. Chen, Q. Wang, L. Sun, S. Wei and Z. Guo
keywords：Magnetic polystyrene nanocomposites, magnetite nanoparticles
source：期刊
specific source：Macromolecular Materials and Engineering
Issue time：2013年
olystyrene (PS)/magnetite (Fe₃O₄) polymer nanocomposites (PNCs) are successfully synthesized by a solvent extraction method. Scanning electron microscopy reveals that the nanoparticles are well distributed in the PS matrix with 5, 10, and 20?wt% without obvious agglomeration. Fourier transform infrared spectroscopy analysis indicated that the PS/Fe3O4 PNCs are synthesized with strong interaction between PS and nanoparticles. The thermogravimetic analyzer and microscale combustion calorimetry reveal an enhanced thermal stability and reduced flammability. The differential scanning calorimetry demonstrates both glass transition temperature (T_g) and melting temperature (T_m) increased with increasing the Fe3O4nanoparticle loading. The observed monotonically decreased complex viscosity indicates a strong shear thinning behavior in the PNCs; meanwhile, the percolation takes place in the low frequency range (0.1–1?Hz) when the nanoparticles are introduced in the matrix. The T_g of the PS/Fe₃O₄ nanocomposites determined from the dynamic mechanical analysis shifts to a higher temperature compared with that of pure PS. Enhanced dielectric properties relate to the Fe₃O₄ NP loadings. In addition, the PS/Fe₃O₄ PNCs exhibit superparamagnetic behavior at room temperature.