Synthesis, characterization and scale inhibition performance evaluation of novel dendrimers with the initiator core of pentaerythritol derivative

Abstract

In this work, a series of novel poly(amido amine) dendrimers with the initiator core of pentaerythritol derivative (denoted by PER-PAMAMs), environment-friendly phosphorus-free scale inhibitors, were synthesized through Michael addition reaction and amidation reaction by divergent approach. The chemical structures and functional groups of the synthesized products of different generations were characterized by Fourier transform infrared spectroscopy (FT-IR) and Nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR) techniques. The scale inhibition performance of PER-PAMAMs dendrimers on silicate scale and calcium carbonate scale was investigated by static scale inhibition experiments. The influences of concentration, working temperature, and pH value on the scale inhibition performance were evaluated systematically. The results indicate that PER-PAMAMs have good scale inhibition performance on both silicate scale and calcium carbonate scale, and 1.0G PER-PAMAM is superior to 2.0G PER-PAMAM. Furthermore, good synergistic effects were observed between PER-PAMAMs and PAPEMP, the silicate scale inhibition rate (24 h) of the composite formula, PER-PAMAM 1.0G (80 mg/L)/PAPEMP (15 mg/L), can reach about 95%. The calcium carbonate scale inhibition rate of the composite formula, PER-PAMAM 1.0G/PAPEMP (10 mg/L), can reach about 95%. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were applied to analyze the scale depositions to deduce the underlying mechanisms.