Description

4,4'-Dinitrostilbene-2,2'-Disulfonic Acid is a key aromatic sulfonic acid derivative and a vital chemical intermediate in the synthesis of optical brighteners and dyes. Its primary value lies in its role as a precursor for stilbene-based fluorescent whitening agents (FWAs), which are essential for enhancing the brightness and whiteness of paper, textiles, and detergents. This compound is critically needed by manufacturers in the specialty chemicals, textile auxiliaries, and detergent industries for producing high-performance additives.

Application

• Primary Intermediate for Fluorescent Whitening Agents (FWAs): The most significant application is as a key building block in the synthesis of stilbene-type optical brighteners used in laundry detergents and fabric softeners.
• Paper Brightening: Used in the production of brightening agents for high-quality papers, including printing and writing grades, to achieve superior whiteness and opacity.
• Textile and Fiber Treatment: Serves as an intermediate for brighteners applied to synthetic fibers like polyamide and polyester, as well as cotton, to improve visual appeal.
• Plastics and Polymer Additive: Employed in the manufacture of brightening agents for plastics to counteract yellowing and enhance the perceived brightness of finished products.
• Research & Development: Utilized in organic synthesis laboratories for developing new dye molecules, fluorescent probes, and specialty chemical compounds.
• Industrial Dye Synthesis: Acts as a sulfonated intermediate in the production of certain anionic dyes and pigments, leveraging its disulfonic acid groups for solubility and affinity.

Basic Information

Product Name	4,4'-Dinitrostilbene-2,2'-Disulfonic Acid
CAS No.	128-42-7
Molecular Formula	C₁₄H₁₀N₂O₁₀S₂
Molecular Weight	430.37 g/mol
Synonyms	4,4'-Dinitro-2,2'-stilbenedisulfonic Acid; DNS Acid; Dinitrostilbenedisulfonic Acid; 2,2'-(1,2-Ethenediyl)bis[5-nitrobenzenesulfonic Acid]; 4,4'-Dinitrodibenzyl-2,2'-disulfonic Acid; Brightener Intermediate; Fluorescent Brightener 220 Intermediate; DNDS Acid
EINECS	204-891-5

Quality Control

Our production of 4,4'-Dinitrostilbene-2,2'-Disulfonic Acid adheres to stringent quality management protocols to ensure batch-to-batch consistency and reliability for industrial synthesis. Each lot undergoes comprehensive analysis, including assay by HPLC, purity checks, and control of key impurities. Certificates of Analysis (COA) detailing all specifications are provided with every shipment to support your quality assurance and regulatory needs.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). The product is light-sensitive and should be handled accordingly to prevent degradation. Keep away from strong oxidizing agents and strong bases.

Specification

Item	Specification
Appearance	Yellow to yellowish-brown crystalline powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 98.0%
Loss on Drying	≤ 1.0%
Sulfated Ash	≤ 0.5%
Heavy Metals (as Pb)	≤ 20 ppm
Related Substances (HPLC)	Individual impurity ≤ 0.5%; Total impurities ≤ 2.0%

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.