Deep eutectic solvent: a green and sustainable alternative for the synthesis of copper phthalocyanine blue and its value added applications

Abstract

PurposeThis paper aims to propose a simple, effective and environmentally benign method for the synthesis of commercially important pigment copper phthalocyanine (PC) blue has been developed using deep eutectic solvent (DES).Design/methodology/approachDES prepared from choline chloride and urea is used as a reaction medium, as well as a source of ammonia. The design of the experiment and factorial design study has proved that the milder reaction conditions with high yields and reusability of DES are the key features of the present study.FindingsThe synthesized pigment is obtained at milder reaction conditions with excellent yield, which can be seen from the design of experiments done for the optimization of results.Practical implicationsThe synthesized pigment was used as a colorant in epoxy-based paint and in screen ink, which gave satisfactory results with respect to color values and stability.Social implicationsThe screen ink prepared was formulated considering environmental aspects to avoid the use of solvents. Biodegradable components were added to the colorant to make the ink environment friendly.Originality/valueReactions occur at moderate temperatures without affecting the time factor, thus, it saves energy. A simple, effective and environmentally benign method for the synthesis of commercially important copper PC has been developed using DES. After the first batch, DES synthesized can be reused as a reaction medium where only a stoichiometric amount of urea is to be added. Simple work up, high yield and purity are achieved.