Corrosion inhibition of aluminum (Al) in hydrochloric acid by anionic polyelectrolyte chondroitin-4-sulfate (CS)
polysaccharide has been studied using both gasometrical and weight-loss techniques. The results drawn from
these two techniques are comparable and exhibit negligible differences. The inhibition efficiency was found to
increase with increasing the inhibitor concentration and decreased with increasing temperature. The inhibition
action of CS on Al metal surface was found to obey both of Langmuir and Freundlich isotherms. The factors
affecting the corrosion rates such as the concentration and geometrical structure of the inhibitor, concentration
of the corrosive medium, and the temperature were examined. The kinetic parameters were evaluated and a
suitable corrosion mechanism consistent with the results obtained is discussed.