It is the earliest product used in China, the product of the sulfonation of naphthalene with sulfuric acid and condensation with formaldehyde. It is an anionic surfactant. Depending on the product, this type of water-reducing agent can appear as a light yellow to dark brown powder, easily soluble in Water, and has a good dispersion effect on many powder materials, such as cement, with a water-reducing rate of up to 25%. The synthesis route of naphthalene sulfonate water reducing agent is as follows: naphthalene → sulfonation → hydrolysis → condensation → neutralization → filtration → drying → the raw material for the production of the product is naphthalene. First, the sulfonation reaction is conducted with concentrated sulfuric acid, and the molar ratio of naphthalene to sulfuric acid is 1:1.3-1.4. The temperature is 160-165 ℃, and the reaction time is three h. Then, the reactant is cooled to 120 ℃ for hydrolysis. Currently, 13-naphthalene sulfonic acid is stable, while d-naphthalene sulfonic acid is easily hydrolyzed, reducing the amount of b-naphthalene sulfonic acid to facilitate the following polycondensation reaction. The hydrolysis time is about 30 minutes. The condensation reaction is essential in the production of b-naphthalene sulfonate water-reducing agent. The sulfonated naphthalene is condensed with formaldehyde at a specific temperature to form a polymer compound. This step of reaction strongly affects the performance of the product. To find the optimal process parameters, the uniform design method was used to investigate the effects of condensation time, condensation temperature, and the ratio of formaldehyde to naphthalene on the product performance. The optimal temperature condition is 104 ℃; The optimal reaction time is 6 hours; The optimal condition for the amount of formaldehyde is 0.75; The maximum expected theoretical value is 18.3. If you are looking for high quality, high purity and cost-effective water reducing agent, or if you require the latest price of water reducing agent, please feel free to email contact mis-asia.