Dispersion of surface-modified nano-Fe3O4 with poly(vinyl alcohol) in chiral poly(amide-imide) bearing pyromellitoyl-bis-l-phenylalanine segments

摘要

In this study, iron oxide (Fe3O4) nanoparticles (NPs) were treated with biodegradable poly(vinyl alcohol) (PVA) as a coupling agent, which could improve the organic functional groups on the surface of Fe3O4 NPs. Then, an optically active poly(amide-imide) (PAI) was produced through a solution polycondensation of N,N-(pyromellitoyl)-bis-l-phenylalanine with 4,4-diaminodiphenyl sulfone. Finally, PAI/modified-Fe3O4 nanocomposites (NCs) containing 2, 4, and 8 % of NPs were successfully fabricated using ultrasonic irradiation technique as a green and safe synthetic method. The effect of PVA coupling agent on the properties and morphology of Fe3O4 NPs and the interaction between Fe3O4 NPs and PAI chains were studied by different techniques. Fourier transform infrared spectroscopy and X-ray diffraction pattern showed that the PVA was coated on the surface of Fe3O4 NPs. Thermogravimetric analysis indicated that the thermal stability of NCs was enhanced in comparison with the neat polymer, and microscopy electron analyses showed homogenous dispersion of modified Fe3O4 NPs in the PAI matrix