title: Development of poly(aspartic acid-co-malic acid) composites for calcium carbonate and sulphate scale inhibition.
abstract: Polyaspartic acid (PSI) is suitable for the inhibition of inorganic scale deposition. To enhance its scale inhibition efficiency, PSI was modified by reacting aspartic acid with malic acid (MA) using thermal polycondensation polymerization. This reaction resulted in poly(aspartic acid-co-malic acid) (PSI-co-MA) dual polymer. The structural, chemical and thermal properties of the dual polymers were analysed by using scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry and gel permeation chromatography. The effectiveness of six different molar ratios of PSI-co-MA dual polymer for calcium carbonate and calcium sulphate scale inhibition at laboratory scale batch experiments was evaluated with synthetic brine solution at selected doses of polymer at 65-70°C by the static scale test method. The performance of PSI-co-MA dual polymer for the inhibition of calcium carbonate and calcium sulphate precipitation was compared with that of a PSI single polymer. The PSI-co-MA exhibited excellent ability to control inorganic minerals, with approximately 85.36% calcium carbonate inhibition and 100% calcium sulphate inhibition at a level of 10 mg/L PSI-co-MA, respectively. Therefore, it may be reasonably concluded that PSI-co-MA is a highly effective scale inhibitor for cooling water treatment applications.
authors.affiliation: a Composites Research Group, Department of Mechanical Engineering , Durban University of Technology , Durban , South Africa.
authors.forename: N
authors.initials: N
authors.lastname: Mithil Kumar
authors.forename: Sanjay Kumar
authors.initials: SK
authors.lastname: Gupta
authors.forename: Dani
authors.initials: D
authors.lastname: Jagadeesh
authors.forename: K
authors.initials: K
authors.lastname: Kanny
authors.forename: F
authors.initials: F
authors.lastname: Bux
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D002133:Calcium Sulfate / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D011232:Chemical Precipitation; D002850:Chromatography, Gel; D010455:Peptides / Q000138:chemical synthesis*; D011091:Polyesters / Q000138:chemical synthesis*; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D010455:Peptides; D011091:Polyesters; C576175:poly(aspartic acid-co-lactic acid); D002119:Calcium Carbonate; D002133:Calcium Sulfate
keywords: aspartic acid; malic acid; polycondensation polymerization; scale inhibitor; water treatment