Polymelamine sulphonate (PMS) are generally more expensive and less effective than PNS dispersants. However, PMS dispersants are more compatible with polyvinyl alcohol based fluid loss control additives than PNS dispersants.
The product is commercially available as both a liquid and a solid. The molecular weight of is from 20 to 40 kg/mol corresponding to the number of repeat units (n) from 50-100. However, there may be some fractions present with up to 250 repeat units.
PMS dispersants can be used at temperatures up to 120°C (248°F).
PMS dispersants are also claimed to be more effective than PNS dispersants in slurries containing micro-silica. See the French patent application FR2622572A1.