Regulation of interfacial properties of polybenzoxazine for effective removal of Cr(VI) from aqueous solution

A novel polybenzoxazine for effective removal of Cr(VI) from aqueous solution has been fabricated by using inexpensive CuCl2-melamine complex, bisphenol A and formaldehyde. In the curing process of benzoxazine monomer, different curing media can guide the directional distribution of functional groups of different polarity in the benzoxazine monomer, and thus can achieve the effect of regulating the interfacial properties of polybenzoxazine, and achieved an amine-rich surface and a suitable surface morphology by changing the monomer structure and the ratio of raw materials. This novel polybenzoxazine sorbent was characterized by using high-resolution scanning electron microscopy, energy dispersive spectrometer, Fourier transform infrared spectroscopy and thermogravimetric analysis. The experimental maximum removal efficiency for Cr(VI) was up to 96.7% and adsorption capacity was 116.32 mg/g at solution pH of 2 with temperature of 25 degrees C. Langmuir model was successfully fitted with various curves obtained at different temperatures, and the kinetic data were well described by pseudo-second-order model. The novel polybenzoxazine absorbent promises such advantages as high removal efficiency, low cost, facile fabrication and good recycling performance.