Sodium Naphthalene Sulfonate

Sodium Naphthalene Sulfonate is a kind of naphthalene based superplasticier and is widely used in concrete. It is also known as many other names, such as, naphthalene sulfonate, naphthalene sulfonate formaldehyde, sulphonated naphthalene formaldehyde, poly naphthalene sulfonate, sodium polynaphthalene sulfonate, naphthalene sulfonic acid. Or more simply, SNF/PNS/FND/NSF. Naphthalene sulfonate, a derivative of sulfonic acid containing naphthalene functional unit, is a naphthalene series super plasticizer with strong dispersing effect on cement particles. SNF superplasticizer has a good effect on the preparation of large-fluid concrete, and has obvious effects on cast-in-place concrete and prefabricated components with early strength and high strength requirements. It can comprehensively improve various properties of concrete.

1.  Widely used in the construction industry, SNF superplasticizer can help prepare free-flowing and pumpable concrete mixtures.  It is also a raw material for composite accelerator, antifreeze and retarder in different construction industries.
2. Use Poly naphthalene sulfonate PNS to improve the rheological and mechanical properties of concrete. For example, reduce the use of water, reduce the water-cement ratio by up to 30% by dispersing cement particles and destroying cement agglomerates. It is especially necessary in the case of high-strength concrete.
3. Use naphthalene sulfonic acid in the prestressed components and high-range concrete for the construction of highways, bridges, tunnels, water conservancy and hydropower projects, ports, wharves, skyscrapers, power engineering, industrial and civil buildings.
4. Naphthalene based superplasticizer is suitable for many types of concretes. Including high-strength concrete, high-performance concrete, steamed concrete, large-fluid concrete, pumped concrete, etc.
5. Meanwhile, naphthalene sulphonate is also widely used in agriculture, plastics, rubber, papermaking, construction, textile, petroleum and other industries.

6. Polynaphthalene sulfonate is an anionic surfactant, its molecular chain length is between small molecules and macromolecules, and the degree of polymerization is about 7-15. That is, the molecular weight of its molecules is not uniform, it is two kinds of small molecules the condensate. It doesn’t affect the setting time of concrete, has low air entrainment, and can greatly reduce the water-cement ratio of concrete. Therefore, under the condition that don’t affect the workability of concrete, the high grade concrete with fluidity can be prepared.

When using porous aggregate, it is advisable to add water and stir first, then add naphthalene sulfonate formaldehyde water reducing agent.

When the slump is large, the vibrating time should not be too long to prevent bleeding and stratification.

Use it after being formulated into a solution of the required concentration.

Use SNF powder directly, or add it after the cement aggregate is fully moistened with 60% mixing water.

The sulphonated naphthalene formaldehyde superplasticizer has good adaptability with other concrete chemical admixtures. It can be widely used as the composition of composite additives, and compounded into special functional additives, such as pumping agent, waterproofing agents, air-entraining water reducer admixtures, antifreeze agent, etc.

Naphthalene-based superplasticizer contains high-concentration PNS with NaSO4 content<5% and low concentration PNS with Na2SO4 content>5%.  The naphthalene sulfonate for sale in our company includes SNF-A, SNF-B, SNF-C with different Na2SO4 content.

• The increase of the content of Na2SO4 in naphthalene superplasticizer can improve the fluidity of cement paste, increase the compressive, flexural strength of concrete, the resistance to chloride ion penetration, and the resistance to carbonization. But it will adversely affect the shrinkage and deformation properties of concrete.
• With the increase of sodium sulfate content in naphthalene-based water reducing agent, the corresponding dispersibility will decrease, and the compressive strength of concrete at different ages will decrease.
• Excessive incorporation of Na2SO4 will increase the alkali content in the concrete, accelerate the hydration, hardening and water loss in the cement paste, generate greater restraint stress and weaken the crack resistance. The incorporation of sodium sulfate will accelerate the hydration rate of cement, release a large amount of heat of hydration quickly and concentratedly. Thus leads to an increase in internal temperature, causes greater temperature stress and cracks.
• The content of Na2SO4 within a certain range(3%-19%) can improve the fluidity of the cement paste. 
• Under the premise of a certain amount of water reducing agent, adding sodium sulfate can increase the early strength of concrete. 
• As the content of sodium sulfate increases, the early drying shrinkage of concrete increases significantly. Among them, when the Na2SO4 content is 10%, the drying shrinkage value of concrete reaches the maximum.
• The cracking property of concrete gradually increases with the increase of Na2SO4 content, and the crack width shows an increasing trend.
• When increasing the Na2SO4 content in a lower range. It can improve the ability of concrete to resist carbonization and chloride ion penetration.

In general, raw material for production of naphthalene based superplasticizer is industrial naphthalene, sometimes refined naphthalene. The production process is as follows. The preparation of powdery sodium naphthalene sulfonate requires a series of processes, such as sulfonation, hydrolysis, condensation, neutralization, filtration, and spray drying, etc. The production of SNF superplasticizer is mature and its performance is stable.

The concrete water reducer can be used directly in concrete, and the effect of over-mixing or under-mixing on concrete performance can be predictable. In addition, naphthalene based superplasticizer has good adaptability with other admixtures and can be widely used as the composition of composite admixtures, such as, pumping agents, waterproofing agents, air entraining water reducing agents and antifreeze agents, etc.