The homogeneous crystallization of magnesium hydroxide (Mg(OH)(2)) was carried out at 97 degrees C in the absence and presence of low molar mass (M-n <= 2000) poly(acrylic acid) (PAA) terminated with different end groups. A significant decrease in Mg(OH)(2) crystal growth was found in the presence of PAA, with relatively hydrophobic end-groups being most effective. The end-groups that were most effective were decyl isobutyrate which are more hydrophobic than the hexyl isobutyrate end-groups previously shown to be maximally effective in inhibiting calcium carbonate and calcium oxalate scaling.