In the present work a variety of polymers with different functional groups and molecular weight
(MW) were tested as gypsum scale inhibitors. The polymers tested include: poly(acrylic  acid)  PAA;
 poly(maleic  acid),  PMA;  poly(aspartic  acid),  PASP; poly(epoxysuccinic acid), PESA;
carboxymethyl inulin (CMl-25); copolymers of maleic acid:sulfonated styrene, PMAS); maleic
acid:vinyl pyrrolidone, PMVP. The results indicated that performance of polymers strongly depends
on the polymer architecture. Based on the data collected, the polymers may be ranked as follows:
PAA> PMA > PASP > CMl-25 >PESA.Among the maleic acid based copolymers the performance ranking is as follows: PMA > PMAS > PMVP1 (MW 15k) > PMVP2 (MW 60k).
The influence of divalent metal ions (i.e., Cu, Zn, Mn) and trivalent metal ions (i.e., Al, Fe) as
gypsum scale inhibitors was investigated. It was found that divalent and trivalent metal ions are
ineffective gypsum scale inhibitors. Results also reveal that trivalent metal ions exhibit
antagonistic effect on polymer performance. This study also presents results on the effect of a
variety of surfactants (i.e., ionic, non-ionic, cationic) on polymers performance. Data reveal that
whereas all surfactants are ineffective gypsum inhibitors, the presence of low concentrations of
cationic surfactant (e.g., cetyltrimethyl ammonium chloride), CTAC, shows negative impact on
polymer performance.