Synthesis of stimuli‐responsive ionic cyclopolymers in search of phosphorous‐free antiscalants

Abstract

Ammonium persulfate‐initiated cyclopolymerization of maleic acid (HO2CC=CCO2H) (MA) with diallylamine (–NR2, R = CH2 = CH‐CH2) derivatives (DADs): R2NH+CH2CO2− (I), R2NCH2CO2−Na+ (II), R2NCH2CO2Et (III), R2NH+(CH2)3CO2− (IV), R2N(CH2)3CO2Et (V), R2NH+(CH2)3SO3− (VI) and R2N(CH2)3SO3−Na+ (VII) gave a series of new pH‐responsive alternate copolymers: –[(DAD‐alt‐MA)]n– VIII‐XIV, respectively. Homopolymers XV and XVI of the corresponding monomers IV and V·HCl were also synthesized. The evaluation of the synthesized polymers as potential antiscalants in reverse osmosis (RO) plants was examined. An effective scale inhibitor must arrest the formation of scale for a residence time (≈15 min) of feed water in the RO chamber. R2NH+(CH2)3CO2− (IV)‐alt‐MA copolymer XI at a concentration of 5 ppm imparted 99% scale inhibition for 360 min, while at 2.5 and 1 ppm concentrations, the CaSO4 scale inhibitions were found to be 99% and ≈ 100% during 120 and 20 min, respectively, at 40°C. Homopolymers XV and XVI, at a 20‐ppm concentration, demonstrated ≈ 95% efficiency in inhibiting mild steel corrosion in 1 M HCl. In some important oilfield applications, requirement of simultaneous scale and corrosion inhibition make these polymers potential candidates for desalination and oilfield applications.

Sustainable Membrane-Based Wastewater Reclamation Employing CO2 to Impede an Ionic Precipitation and Consequent Scale Progression onto the Membrane Surfaces

“…This viscid layer seems to be a part of biofouling, as highlighted by an earlier study [ 32 , 33 ]. It has been noticed in earlier studies that the nutritive role of polyacrylate- and polyphosphonate-derived antifouling agents may cause biofouling during operation of RO membranes [ 34 ]. The spacer’s condition contributes significantly to maintaining the consistent permeate flux by RO membrane, and any blockage or malfunctioning in spacers causes serious deterioration in membrane performance [ 35 ].…”

Synergistic effect of KI on the corrosion inhibition of a poly(diallylammonium chloride)-based cyclocopolymer containing bis-cationic motifs for mild steel corrosion in 20% formic acid

“…The assignments of NMR peaks are based on numerous earlier works. [35][36][37] The absence of residual alkene signals for monomer 2 in the 1 H-(Fig. 2a) and 13 C-NMR spectrum (Fig.…”

Stimuli‐Responsive Macromolecular Architecture by Butler Cyclopolymerizations: Synthesis and Applications

“…In search of phosphate‐free antiscalants – phosphates are detrimental to ecology, a series of homo‐ and maleic acid copolymers having CH 2 and (CH 2 ) 3 spacers in the pendants have been synthesized (Scheme 10). [58] Maleic acid 4 is led to the alternate copolymers. PZ 57 displayed a PSI of≈100 % for 60 min at a concentration of 2.5 ppm.…”