Pyridine-poly(urethane ester amide) coatings from linseed oil

A novel attempt has been made to develop the room temperature cured polyesteramide resin by condensation polymerization reaction between fatty amide diol (N,N-bis 2-hydroxy ethyl linseed oil fatty amide) obtained from oil of linseed (Linum ussitatissimum seeds) and pyridine dicarboxylic acid (PyA) to develop pyridine polyesteramide (Py-PEA), which was further treated with toluylene-2,4-diisocyanate (TDI), in different weight percentages to develop a series of pyridine poly(urethane esteramide) resins (Py-UPEA). The structural elucidation of Py-PEA and Py-UPEA were carried out by FT-IR, ¹H-NMR and ¹³C-NMR spectroscopic techniques. Physico-chemical characterizations of these resins were performed by standard laboratory methods. Thermal analyses of these resins were accomplished by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. Coatings of Py-UPEA were prepared on mild steel strips to evaluate their physico-mechanical and chemical/corrosion resistance performances under various corrosive environments. It was found that among all these systems, the sample having 14 wt% loading of TDI showed the best physico-mechanical and corrosion resistance performances. Thermal stability performance suggest that the system could be safely used up to 200 °C.