Synthesis and Characterization of Green Polyurethane Coatings Derived from Niger‐Seed‐Oil‐Based Polyesteramide Polyols

Abstract

Polymeric researchers are trying to use renewable resources for polymeric resins in the coating industry to reduce fossil or petroleum feedstock reliance significantly. The present research attempts to develop a polyurethane (PU) coating for the first time from Niger seed oil (NSO). The polyesteramide polyols are synthesized by amidation of Niger seed oil with diethanolamine and further esterification with different biobased dicarboxylic acids (phthalic, itaconic, and dimer) to introduce a required functionality of hydroxyl group. Spectroscopic studies of Niger‐seed‐oil‐based fatty diethanolamide and polyesteramide polyols are carried out by Fourier‐transform infrared spectroscopy and proton nuclear magnetic resonance. The polyurethane coatings are prepared from synthesized polyesteramide polyols and hexamethylene diisocyanate biuret (HDI‐B). The cross‐link density of PU coatings demonstrated by gel content method and the corrosion study is carried by salt water immersion technique. The PU coatings are also studied for glass transition temperature (Tg) and thermal stability by differential scanning calorimetry and thermogravimetric analysis. Practical Applications: The long aliphatic chain provides flexibility, whereas the rigid structure of polyols enhances the hardness of PU coating. The phthalic‐based PU metal coatings depict excellent hardness, gloss, hydrophobicity, and chemical resistance compared to itaconic and dimer‐acid‐based PU.

Polyurethane as a versatile polymer for coating and anti-corrosion applications: A review

“…The mechanical and anticorrosive capabilities of all the coatings increased progressively as the NCO/OH ratio rose. Niger seed oil (NSO) was used by Ranjeet et al [29] to create a PU covering (Figure 7). Niger seed oil is amidated with diethanolamine to create polyesteramide polyols, which are then esterified with several biobased dicarboxylic acids (phthalic, itaconic, and dimer) to add the necessary hydroxyl group functionality.…”

Development of a Catalyst System for Enhanced Properties of Coconut Diethanolamide-Based Rigid Poly(urethane-urea) Foam

“…In our ongoing pursuit of sustainable development, the PU industry significantly emphasizes adopting vegetable-oil-based polyols as a viable alternative to traditional petrochemical equivalents . According to several studies, ,,,− diethanolamide (DEA)-modified vegetable-based polyols have emerged as promising alternatives for petroleum-based polyols for PU synthesis because of their autocatalytic properties allowing mild amounts of catalyst in PU synthesis. ,,, Two of the valuable derivatives are coconut fatty acid diethanolamine (CFAD) and coconut diethanolamine (CDEA), obtained mainly via amidation of CO, which show promising potential as CDEA-based polyols for the development of biobased PU foams. Consequently, the inherent autocatalytic effect of the amine moieties present in CDEA altered the standard catalytic formulation, creating a disparity between gelling and blowing reactions, affecting foam structure and properties …”