Synthesis, characterisation and utilisation of hyperbranched poly (ester‐amide) for the removal of some anionic dyestuffs from their aqueous solutions

Abstract

PurposeThe purpose of this paper is to show how to remove some dyestuffs, as pollutants, from their aqueous solutions.Design/methodology/approachTo achieve the goal, a water soluble hyperbranched poly (ester‐amide) (HBP) was synthesised using the melt polycondensation method by the reaction of maleic anhydride (MA) and diisopropanol amine (DIPA) at 140°C at a molar ratio of 1:1.3 MA: DIPA, respectively. This HBP was incorporated in the preparation of an effective microcrystalline cellulose (MCC)/dimethyloldihydroxyethylene urea (DMDHEU)/HBP adduct by crosslinking HBP with DMDHEU in presence of MCC. Furthermore, the prepared adduct was characterised by investigation its infra red and then utilised in the removal of three anionic dyestuffs from aqueous solutions, namely Irgalan Blau 3GL (an acid dye), SIRIUS Blau S‐BRR (a direct dye) and Levafix Brill Orange P‐GR (a hydrolysed reactive dye).FindingsThe results obtained revealed that the optimum conditions for preparing MCC/DMDHEU/HBP adduct are [HBP], 90 g/l; [DMDHEU], 200 g/l; LR, 1/3.3; [NC4LH], 20 g/l; a time of 30 min and a temperature of 160°C. Moreover, the results also showed that the extent of removal of such dyestuffs from their aqueous solutions by the prepared adduct follows the order: reactive dye>acid dye>direct dye, it is more pronounced at lower than at higher pH values and the removal of each dye by that adduct follows a first‐order reaction.Research limitations/implicationsOther substrates such as chitosan can be used to prepare more effective adducts.Practical implicationsHyperbranched polymers can be used effectively to prepare ion exchangers capable of removing the pollutants of dyestuffs from their aqueous solutions.Originality/valueThe aforementioned prepared HBP is a novel hyperbranched polymer and could be applied in the removal of many other pollutants.