Investigation of Poly(N-alkyl-4-vinylpyridinium) Cross-Linked Bromides with Biomaterial Properties as Corrosion Inhibitor

The new biomaterial applicable polymer, poly (N-alkyl-4-vinylpyridinium) bromide, has been synthesized for various works, such as surface modification, electrochemical sensors, fabrication of antibacterial surfaces, and water purification. The quaternization of poly(4- vinyl pyridine) cross-linked with 2% DVB was done by four alkyl bromides (butylbromide ([P₄-VP]-BBr), octane bromide ([P₄-VP]-OBr), cyclohexane bromide ([P₄-VP]-CHBr), and cyclopentane bromide ([P₄-VP]-CPBr)) in acetonitrile at room temperature. Then, their inhibitory effects were studied against the corrosion of St-37 in 1-M H₂SO₄ solution. The inhibitors formation was confirmed by energy-dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FT-IR) techniques. Furthermore, their inhibition performance was investigated with the aim of potentiodynamic polarization (Tafel) and electrochemical impedance spectroscopy (EIS). According to the obtained results, four polymers can effectively protect carbon steel from corrosive ions and the inhibition efficiency (%E) has a direct relationship with the inhibitor concentration and increasing 87.41% at 0.04 g L⁻¹ [P₄-VP]-CPBr in 1-M H₂SO₄. In addition, the corrosion current density reduces from 398.11 × 10⁻⁶ A·cm − ² in the blank condition to 50.11 × 10⁻⁶ A·cm⁻². The data demonstrated that the corrosion inhibition order of polymers is [P₄-VP]-CPBr > [P₄-VP]-BBr > [P₄-VP]-OBr > [P₄-VP]-CHBr.