Renewable Source Based Non‐biodegradable Polyurethane Coatings from Polyesteramide Prepared in One‐Pot Using Oleic Acid

Abstract

AbstractThe highlight of the work was the preparation of polyesteramide in a one‐pot reaction which avoids isolation of diethanol amide as it is normally required in polyesteramide preparation. In the present work, oleic acid was reacted with diethanol amine resulting in diethanol amide which further reacted with phthalic anhydride in the same reaction vessel without isolation and purification. Therefore the reaction is a one‐pot, time‐saving and cost‐effective method as it requires minimum solvent and processing steps. In addition to this, the fatty acid used was a single fatty acid (oleic acid) that provides selective physico‐ chemical and anticorrosive properties for the resin. FT‐IR and 1H‐NMR spectroscopic studies confirmed the structure of the polyesteramide. End group analysis and molecular weight were used to calculate the stoichiometric balance of the NCO/OH ratio in the preparation of polyurethane. The prepared resin was converted to polyurethane coatings by reacting with toluene diisocyanate and methylene diphenyl diisocyanate. Thermal stability, physico‐chemical and coating properties of the polyurethane coatings were investigated. The polyurethane prepared showed a non‐biodegradable nature so that it is of commercial interest and value for applications in various fields. Study of coatings was also carried out for properties like adhesion, impact resistance, pencil hardness and the bending test.