Development of eco-friendly polyurethane coatings based on neem oil polyetheramide

Abstract

Renewable sources like vegetable oils have been used to prepare many polymeric resins and the topic is gaining more importance due to the functional attributes to structure of oils. In the regard, renewable source based polyurethane coatings have been prepared from polyetheramide of neem oil in the laboratory. In the preparation of polyetheramide, first neem oil was allowed to react with diethanol amine. Obtained fatty amide was modified to the polyetheramide by reacting it with bisphenol-A. Spectroscopic techniques such as FT-IR and 1H NMR confirmed the structures of fatty amide and polyetheramide. Polyurethane coatings were prepared from the polyetheramide by treating it with methylene diphenyl diisocyanate.Coating properties such as gloss, scratch hardness, adhesion, flexibility, thermal stability, impact and chemical resistances were evaluated using standard methods. The influence of surface modified TiO2 nano particles on the properties of the neem oil based polyurethane coatings was examined by loading nano TiO2 from 0 to 4%. The overall performance of coatings revealed that neem oil based polymeric coatings can be successfully used as coatings in industrial applications.