Sintesis Polifenalkamin dari Kardanol Hasil Isolasi Kulit Biji Mete (Anacardium occidentale.L) dengan Variasi Mol Formladehida Serta Uji Antikorosi dan Antibakteri

Abstract

Polyphenalkamine was synthesized via a Mannich reaction between cardanol, ethylenediamine, and formaldehyde. The synthesis was carried out by mixing cardanol, ethylenediamine, and formaldehyde under reflux for 3.5 hours. The parameter investigated in this study was the variation of formaldehyde amount at 0.05, 0.075, and 0.10 mol, which resulted in yields of 51,25% ; 53,77% ; and 49,33%, respectively. The obtained polyphenalkamine was characterized by FT-IR spectroscopy, corrosion inhibition testing, thermogravimetric analysis, and antibacterial activity assays.The FT-IR spectra confirmed the formation of polyphenalkamine by the appearance of new absorption bands in the range of 3500–3100 cm⁻¹ corresponding to N–H stretching vibrations, bands at 1690–1640 cm⁻¹ assigned to N–H bending vibrations, and bands at 1350–1000 cm⁻¹ attributed to C–N stretching formed as a result of the Mannich reaction. Corrosion inhibition tests showed weight loss percentages for the polyphenalkamine synthesized with 0.05, 0.075, and 0.10 mol of formaldehyde of 0.9%, 0.1%, and 0.4%, respectively. Thermogravimetric analysis revealed that the sample synthesized with 0.075 mol formaldehyde exhibited a mass loss of 97.3% at a degradation temperature of 108 °C. Antibacterial activity tests indicated inhibition zones against Staphylococcus aureus of 23.5 mm, 31.8 mm, and 26.2 mm, and against Escherichia coli of 11.3 mm, 13.8 mm, and 13.0 mm for the samples synthesized with 0.05, 0.075, and 0.10 mol formaldehyde, respectively.