Mechanically Strong, Hydrophobic, Antimicrobial, and Corrosion Protective Polyesteramide Nanocomposite Coatings from Leucaena leucocephala Oil: A Sustainable Resource

The aim of this research work is to develop polyesteramide [LMPEA] nanocomposite coating material [LMPEA/Ag] using N,N-bis(2-hydroxyethyl) fatty amide obtained from non-edible Leucaena leucocephala [LL] seed oil [LLO], and maleic anhydride, reinforced with silver nanoparticles [SNPs], biosynthesized in Leucaena leucocephala leaf extract. UV, XRD, TEM, and particle size analyses confirmed the biosynthesis of NP (37.55 nm). FTIR and NMR established the structure of LMPEA formed by esterification reaction, without any solvent/diluent. Coatings were mechanically strong, well adherent to substrate, flexibility retentive, hydrophobic, and antimicrobial as evident from good scratch hardness (2-3 kg), impact resistance (150 lb per inch), bend test (1/8 inch), high water contact angle measurement value (109°) relative to pristine LMPEA coating (89°), and broad-spectrum antimicrobial behavior against MRSA, P. aeruginosa, E. coli, A. baumannii, and C. albicans. LMPEA and LMPEA/Ag exhibited high corrosion protection efficiencies, 99.81% and 99.94%, respectively, in (3.5% w/v) NaCl solution for 20 days and safe usage up to 200 °C. The synthesized nanocomposite coatings provide an alternate pathway for utilization of non-edible Leucaena leucocephala seed oil through a safer chemical synthesis route, without the use/generation of any harmful solvent/toxic products, adopting "Green Chemistry" principles.