A. Akar et N. Oz, Low molecular weight poly(acrylic acid) with nitrilodi(methylenephosphonicacid) chain ends for scale inhibition, ANGEW MAKRO, 273, 1999, pp. 12-14
Poly(acrylic acid) with molecular weight of 5000 was produced by using 2-am
inoethanethiol hydrochloride as chain transfer agent. Amine chain end group
s of the resulting polyacrylic acid were transfer med into nitrilodi(methyl
enephosphonic acid) by reacting formaldehyde-phosphorous acid in the presen
ce of hydrogen chloride. H-1 NMR, P-31 NMR and microanalysis were used for
structural analysis. The modified polyacrylic acid had much better calcium
carbonate scale inhibition effect than commercial poly(acrylic acid).