Water-Soluble and Biodegradable Pectin-Grafted Polyacrylamide and Pectin-Grafted Polyacrylic Acid: Electrochemical Investigation of Corrosion-Inhibition Behaviour on Mild Steel in 3.5% NaCl Media

Table 4

Impedance parameters and inhibition efficiency values for mild steel sample in 3.5% NaCl containing various concentrations of Pec-g-PAA.

S. no.	Conc.; (ppm)	𝑅𝑠; (ohms)	𝑅𝑝; (ohms)	𝑅ads; (ohms)	Total resistance; (ohms)	IE; (%)	𝐶ads; 10^−4 F	𝐶dl; 10^−3 F	Surface coverage; (𝜃)	𝑊; ohms s^−1/2
1	Blank	5.018	53.25		58.268			3.721
2	50	6.026	179.4	2.31	187.73	69.0	66.84	0.7793	0.38	122
3	100	6.527	199.1	7.102	212.72	72.6	57.25	0.5582	0.90	194
4	200	6.125	214.2	9.534	229.85	74.7	12.31	0.4794	0.94	188
5	300	8.44	292	13.04	313.48	81.4	10.31	0.2040	0.95	202
6	400	3.125	292.6	43.87	339.59	82.8	8.52	0.1338	0.95	304
7	500	6.101	302	20.91	329.01	82.3	12.51	0.1000	0.88	192