A novel polyaspartic acid derivative with multifunctional groups for scale inhibition application

Polyaspartic acid is a green biodegradable antiscalant and widely applied in water treatment field. However, its scale inhibition efficiency is not prominent, especially for calcium orthophosphate. So we introduced acylamino and hydroxyl groups simultaneously to prepare a novel polyaspartic-acid derivative (PASPTU) with multifunctional groups by the reaction of polysuccinimide with threonine and urea. The graft copolymer was analyzed by using nuclear magnetic resonance, gel permeation chromatography, thermogravimetric analyzer and Fourier transform infrared spectroscopy. Its scale inhibition performance for calcium orthophosphate, calcium sulfate and calcium carbonate was evaluated. The findings showed that the scale inhibition rates of the graft copolymer reached up to 100% for calcium orthophosphate, 100% for calcium sulfate and 91% for calcium carbonate at certain dosages. The findings above showed that the copolymer had excellent scale inhibition efficiency for calcium salts in water treatment processes.

Silicic acid condensation under the influence of water-soluble polymers: from biology to new materials

Silicic acid condensation under the influence of functional polymers is reviewed starting from biology to new materials.

Modified macromolecules in the prevention of silica scale

Silicic acid polycondensation leads to the formation of amorphous silica. This process is of great importance to the survival of certain living organisms, such as diatoms and sponges, but presents a significant problem in various production facilities that use water for heating or cooling. In the latter, amorphous silica can be a recalcitrant deposit that can hamper proper system operation. Hence, inhibition of silicic acid polycondensation by chemical inhibitors is an intensely sought strategy by water system operators. In this manuscript, we report the inhibitory effect of zwitterionic phosphonated analogs (PPEI’s) of the cationic polymeric chemical additive polyethyleneimine (PEI) in mildly supersaturated silica solutions (500 ppm/8.3 mM “Si”) at pH=7. The inhibition efficiency of PPEI’s depends on a variety of parameters, such as concentration and degree of phosphonomethylation of the parent PEI polymer.