Sodium Polynaphthalene Sulfonate (PNS) is an anionic surfactant, emulsion stabilizer, dispersant and suspending agent with a pH range between 7 - 9. This anionic surfactant is hydrotropic meaning it has the ability to enhance the water solubility of another surfactant. As a dispersing agent it finds application in wide number of markets: adhesive as a filler in polymers, water soluble paint, acrylic paint, and latex paint, paper making, textile printing and dyeing, electroplating additive; in pretreatment cleaners, post-treatment trivalent passivates, pigment paste, water treatment, waterborne coatings and even in some cosmetics.
In the construction market PNS plays a very important role as an admixture in concrete known as superplasticizer. PNS plays important role in concrete, cement, gypsum, and mortar mixes. There are three different plasticizers; plasticizer, intermediate plasticizer, and superplasticizer. Each defines water reduction capacity in the concrete mix while the concrete slump is basically unchanged. Concrete plasticizers improve the rheology, mechanical, and flow properties of concrete while increasing concrete strength, promoting compaction, and providing optimium workability. In summary, plasticizers reduce the amount of water and increase the strength of the concrete. Improve the pore structure of concrete and increase its compactness. Reduce the bleeding and segregation of concrete mixture and delay the setting time of the mixture. Save cement consumption and reduce engineering cost and improve the quality of the concrete in the construction project
The lignin, sodium lignosulphonate when added to concrete reduces the water content in the mix by 5% but less than 12% and is known as a plasticizer. Sodium lignosulphonate as an admixture plasticizer achieves three things: first it reduces water consumption and increases the strength of the cement, second it improves the workability and fluidity of the concrete, and third it reduces the amount of cement used and the amount of water to maintain the same strength. However, PNS is a superplasticizer with the ability to reduce the water by 16% up to 25%. It enables contemporary global superstructures such as bridges and high-rises constructed of concrete; flow ability, compressive strength, low air permeability, good resistance to wear and tear, and longevity with economy. There is one other super plasticizer that reduces water by 20 to 35% known as PCE (Polycarboxylate ether superplasticizer), however it is relatively expensive. PNS is an economic workhorse as superplasticizer.
