Papaya (Carica papaya L.) leaves extract as an inhibitor for brass in H2SO4 solution

Abstract

This research aimed to analyze the effect of addition of papaya (Carica Papaya L.)leaves extract on decreasingthe corrosion rate of brass in H2SO4 solution by employingweight loss method. The compositions of inhibitor were varied by 0% v/v; 2% v/v; 4% v/v; 6% v/v and 8% v/v. The tested characteristic includes density, electrical potential, hardness, corrosion rate measurement and microstructure characterization using optical microscope (OM) and characterization of scanning electron microscope-emission diffraction X-ray (SEM-EDX). The results showed that the density and hardness values of brass increased steadily with the immersion time of 6 days. The lowest corrosion rate was obtained by the sample with the composition of 6% v/vof inhibitor concentration, which showed the value of 0.797 × 10−6 g/cm.hour within 3 days and 0.313 × 10−6 g/cm.hour within 6 days, respectively. In addition, the efficiency of papaya leaves extract reached 83.4% at 6% v/v composition inhibitor in 0,05 M H2SO4 medium with 6 days of immersion time.