Synthesis by self-condensing AGET ATRP and solution properties of arborescent poly(sodium 2-acrylamido-2-methyl-N-propane sulfonate)

Assessment of novel maleic anhydride copolymers prepared via nitroxide-mediated radical polymerization as CaSO4 crystal growth inhibitors

Calcium sulfate is one of the dominant scales which, unlike carbonate scale, are not easily removable by acid. To inhibit CaSO₄ scale formation in artificial cooling water systems, well-defined low molecular weight maleic anhydride and n-alkylacrylamide copolymers (YMR-S series) were synthesized via nitroxide-mediated radical polymerization initiated by benzoyl peroxide in the presence of 2,2,6,6-tetramethyl-1-piperidinyloxy at varying concentrations. These polymerizations exhibit living polymerization characteristics; that is, they show linear growth in chain length as a function of monomer conversion, and have narrow molecular weight distributions. Resultant polymers were characterized by means of ¹H-NMR and ¹³C-NMR. The inhibition behavior of these YMR-S series polymers against CaSO₄ was evaluated using the static scale inhibition method and a dynamic tube block test. The inhibition ability on the CaSO₄ scale is 99.5% with 9 ppm dosage level at pH 10.45 and temperature 70°C. Scanning electronic microscope analysis proved the morphological changes of the CaSO₄ scales due to the strong inhibition action of YMR-S polymers. It is also observed that the antiscaling effect of the copolymers greatly depends on the molecular weight, and the optimum range is below 20,000 and approximately in the range 500-2000.

Polymerisation of 2-acrylamido-2-methylpropane sulfonic acid sodium salt (NaAMPS) and acryloyl phosphatidylcholine (APC) via aqueous Cu(0)-mediated radical polymerisation

The scope of aqueous Cu(0)-mediated living radical polymerisation has been expanded with the preparation of poly(2-acrylamido-2-methylpropane sulfonic acid)sodium salt (P(NaAMPS)) and poly(acryloyl phosphatidycholine) (PAPC).