Description

4,4',6,6'-Di-tert-Butyl-2,2'-Thiobisphenol CAS NO 3293-91-2 is a high-purity, sterically hindered phenolic antioxidant and chemical intermediate. This compound is valued for its ability to act as a highly effective stabilizer and chain-breaking antioxidant in demanding polymer and chemical synthesis applications. It is primarily needed by manufacturers in the polymer, lubricant, and specialty chemical industries seeking to enhance the oxidative stability and longevity of their products.

Application

• Polymer Stabilizer: A key antioxidant and light stabilizer for polyolefins (e.g., polyethylene, polypropylene), synthetic rubbers, and engineering plastics to prevent thermal and oxidative degradation during processing and service life.
• Lubricant & Fuel Additive: Used as an antioxidant additive in lubricating oils, greases, and industrial fuels to inhibit sludge formation, viscosity increase, and acid generation.
• Chemical Intermediate: Serves as a crucial building block in the synthesis of more complex phosphite and phenolic antioxidants, as well as other specialty chemicals.
• Adhesive & Sealant Formulations: Incorporated to improve the aging resistance and durability of high-performance adhesives and sealants.
• Elastomer Protection: Protects synthetic elastomers like SBR, NBR, and EPDM from ozone cracking and flex-cracking by scavenging free radicals.

Basic Information

Product Name	4,4',6,6'-Di-tert-Butyl-2,2'-Thiobisphenol
CAS No.	3293-91-2
Molecular Formula	C28H42O2S
Molecular Weight	442.70 g/mol
Synonyms	2,2'-Thiobis(4,6-di-tert-butylphenol); 4,4'-Thiobis(2,6-di-tert-butylphenol); Bis(2,6-di-tert-butyl-4-hydroxyphenyl) sulfide; Antioxidant 300; AO 300; DBSP; Phenol, 4,4'-thiobis[2,6-bis(1,1-dimethylethyl)-]; Lowinox 44B25
EINECS	221-965-6

Quality Control

Our 4,4',6,6'-Di-tert-Butyl-2,2'-Thiobisphenol is manufactured under a strict quality management system. Every batch undergoes rigorous analytical testing to ensure it meets precise specifications for purity, identity, and performance. A comprehensive Certificate of Analysis (COA) detailing assay, impurity profile, and physical properties is provided with each shipment to guarantee consistency and traceability.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). This product is easily oxidized; for long-term storage, maintaining an inert atmosphere (e.g., nitrogen) in the headspace of the container is recommended to preserve efficacy. Keep away from strong oxidizing agents.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to reference spectrum
Assay (HPLC)	≥ 98.0 %
Melting Point	150 - 155 °C
Loss on Drying	≤ 0.5 %
Residue on Ignition	≤ 0.1 %

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