Description

Weston 439 (CAS NO 93356-94-6) is a specialized chemical additive widely recognized for its performance-enhancing properties in polymer and material science applications. Its primary value lies in its ability to act as a highly effective stabilizer, protecting materials from degradation caused by heat, light, and oxidation during processing and end-use. This makes it a critical component for manufacturers in the plastics, rubber, and coatings industries seeking to improve product longevity and durability under demanding conditions.

Application

• As a primary antioxidant and stabilizer in polyolefins (PP, PE) to prevent thermal-oxidative degradation during extrusion and molding.
• Used in synthetic rubber formulations to enhance aging resistance and maintain elastomeric properties.
• Employed as a stabilizing agent in adhesives and sealants to ensure consistent performance and shelf-life.
• An additive in industrial lubricants and greases to inhibit oxidation and viscosity breakdown at high operating temperatures.
• Provides UV and light stabilization in selected polymer applications, complementing other light stabilizers.
• Used in the production of engineering plastics to protect against degradation during high-temperature processing.

Basic Information

Product Name	Weston 439
CAS No.	93356-94-6
Molecular Formula	Contact for details
Molecular Weight	Contact for details
Synonyms	Phosphite antioxidant 439; Tris(2,4-di-tert-butylphenyl) phosphite (common related structure); Antioxidant 439; Weston PPD 439; AO 439; Phosphite stabilizer 439; 2,4-Di-tert-butylphenyl phosphite (derivative); Hostanox PAR 439 (potential trade name)
EINECS	Contact for details

Quality Control

Our production of Weston 439 adheres to stringent quality management protocols to ensure batch-to-batch consistency and high performance. Each lot undergoes rigorous analytical testing, including assay and impurity profile analysis. Certificates of Analysis (COA) documenting purity, physical properties, and other critical parameters are available upon request to support your quality assurance and regulatory compliance 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). Due to its hygroscopic (moisture-sensitive) nature, the container must be kept tightly sealed after initial opening to prevent moisture absorption. For long-term storage, consider using an inert atmosphere to minimize potential oxidation.

Specification

Item	Specification
Appearance	White to off-white powder or flakes
Identification (IR)	Conforms to standard
Assay (HPLC)	≥ 98.0%
Melting Point	Contact for details
Volatile Matter	≤ 0.5%
Acidity (as H3PO4)	≤ 0.1%

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