Polyacrylates have been successfully used over the years as scale control agents. Below is a diagram of polyacrylate where M can stand for any monovalent cation, hydrogen or an ammonium radical.

As was mentioned previously, it is the carboxylic acid salt, COOM, which provides the dispersancy. It is important to note the effectiveness of the polymer decreases as the chain length increases. A length of about 10-15 repeating units is best; at this molecular weight, adsorption without bridging is maximized and dispersion is most efficient.

While many of the more technically advanced polymers available today have displaced polyacrylate for scale control, it is still widely used as an inexpensive alternate deposit control agent. In addition, it still represents one of the more effective materials for inhibiting the formation of calcium sulfate.