Synergistic scale and corrosion inhibiting admixtures containing carboxylic acid/sulfonic acid polymers

An admixture useful for inhibiting the formation of scale forming salts in an aqueous system comprising:

• (a) a water-soluble polymer having a weight average molecular weight of less than 25,000, as determined by light scattering, selected from the group of polymers comprising:
• (i) an unsaturated mono-carboxylic acid selected from the group consisting of acrylic acid and methacrylic acid;
• and
• (ii) an unsaturated sulfonic acid selected from the group consisting of 2-acrylamido-2-methypropyl sulfonic acid and 2-methacrylamido-2-methylpropyl sulfonic acid;
• wherein the weight ratio of (i):(ii) range from about 1:4 to about 4:1;
• and
• (b) at least one member selected from the group comsisting of:
• alkyl phenoxy poly(ethyleneoxy)ethanols and propylene terminated ethylene oxide adducts, low molecular weight homopolymers of maleic acid or anhydride, low molecular weight polyacrylic acids, phosphino carboxylic acid, low molecular weight copolymers of acrylamide and acrylate, about 60/40 copolymers of acrylic acid and 2-hydroxypropyl acrylate, copolymers of maleic acid or anhydride and sulfonated styrene and sulfonated polystyrenes;
• wherein the weight ratio of (a):(b) is about 1:10 to about 10:1.