INVESTIGATION ON CHEMICAL CONSTITUENTS IN DAMMAR RESIN EXTRACT FROM STINGLESS BEE HIVE AND ITS POTENTIAL AS CORROSION INHIBITOR (Penyiasatan Konstituen Kimia dalam Extrak Resin Dammar daripada Sarang Lebah Tanpa Sengat dan Potensinya Sebagai Perencat Kakisan)

This study aimed to determine the major compounds present in local dammar resin and its potential as an anticorrosive property. Dammar resin from a stingless bee hive was subjected to solvent extraction using an aqueous system; 70:30 v/v of ethanol: water. The yield of extraction was characterized through Fourier transform infrared (FTIR) and gas chromatography-mass spectrometry (GC-MS). A linear polarization resistance (LPR), potentiodynamic polarization, and weight loss test were performed to evaluate the corrosion rate of steel. The result shows that longipinane (18) was the major compound present in the extract, followed by ursolic aldehyde (14), 1H-cyclopropeazulene (6.85%), 3,4-dichlorophenyl thiocyanate (6%), azulene, 1,2,3,3a,4,5,6,7octahydro-1,4-dimethyl-7-(1-methylethenyl) (4.48%), and 2,4-heptadienal (4%). The existence of aromatic structure, phenyl group, C=C, and C=O provides an active site for adsorption on the metal surface to inhibit steel corrosion. LPR and weight loss test revealed the lowest corrosion rate at the 600 ppm dammar extract and recorded about 60% and 74% inhibition efficiency respectively. Tafel analysis showed a decrease in current density from 5.8 x 10-3 to 8.0 x 10-4 after 600 ppm dammar extract was employed in the corrosive medium of 3% NaCl, eventually, giving an inhibition efficiency at 86.2%. This research signifies that the local dammar resin of stingless bee hives has great potential as a corrosion inhibitor. © 2023, Malaysian Society of Analytical Sciences. All rights reserved.