Description

Tetrakis(2,4-Di-tert-Butylphenyl)-1,1-Biphenyl-4,4'-Diylbisphosphonite is a high-performance organophosphorus antioxidant and secondary phosphonite stabilizer, widely recognized for its exceptional efficacy in protecting polymers from thermal and oxidative degradation. Its primary value lies in its ability to act as a highly effective hydroperoxide decomposer and color stabilizer, significantly enhancing the longevity and performance stability of sensitive polymer formulations. This compound is essential for manufacturers in the plastics, synthetic fiber, and elastomer industries who require superior processing stability and long-term color retention for their high-value products.

Application

• Polyolefin Stabilization: A key component in antioxidant packages for polypropylene (PP) and polyethylene (PE), protecting against thermal degradation during processing (e.g., extrusion, injection molding) and in end-use.
• Color Stabilization in Engineering Plastics: Used to prevent yellowing and maintain color integrity in polymers like polycarbonate (PC), polyamides (nylon), and polyesters (PET, PBT).
• Synergistic Stabilizer Systems: Employed in combination with primary phenolic antioxidants (e.g., Irganox 1010) and UV stabilizers to create highly effective, multi-functional stabilization systems for demanding applications.
• Fiber and Film Production: Critical for stabilizing synthetic fibers and thin films where high surface area and processing temperatures demand robust protection against melt fracture and oxidative chain scission.
• Adhesive and Sealant Formulations: Enhances the thermal aging resistance of hot-melt adhesives, polyurethane sealants, and other polymer-based bonding agents.
• Elastomer and Rubber Compounding: Protects synthetic rubbers like SBR, EPDM, and NBR from heat buildup and oxidation during curing and in service, extending product life.
• Recycled Polymer Streams: Used to rebuild the stabilization package and restore performance properties in post-consumer and post-industrial recycled plastics.
• Masterbatch and Concentrate Production: Supplied as a pure active ingredient for the manufacture of high-load additive masterbatches, ensuring uniform dispersion in the final polymer matrix.

Basic Information

Product Name	Tetrakis(2,4-Di-tert-Butylphenyl)-1,1-Biphenyl-4,4'-Diylbisphosphonite
CAS No.	38613-77-3
Molecular Formula	C68H92O4P2
Molecular Weight	1035.41 g/mol
Synonyms	Bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite; P-EPQ; Phosphite stabilizer P-EPQ; Irgafos P-EPQ; Tris(2,4-di-tert-butylphenyl) phosphite (common misnomer, but related); Tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite; 4,4'-Biphenylenediyl tetrakis(2,4-di-tert-butylphenyl) phosphite; Antioxidant P-EPQ
EINECS	254-008-5

Quality Control

Our production of Tetrakis(2,4-Di-tert-Butylphenyl)-1,1-Biphenyl-4,4'-Diylbisphosphonite adheres to a stringent quality management system to ensure batch-to-batch consistency and high purity. The product is manufactured and tested in facilities that follow cGMP (current Good Manufacturing Practice) guidelines where applicable. Each batch is accompanied by a comprehensive Certificate of Analysis (COA) detailing key parameters such as assay, melting point, and specific impurity profiles. We support compliance with global regulatory frameworks including REACH and can provide necessary documentation for food contact or other regulated applications upon request.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at a controlled room temperature (15-25°C). Due to its hygroscopic (moisture-sensitive) nature, the container must be kept tightly sealed after opening to prevent absorption of atmospheric moisture, which can lead to hydrolysis and reduced efficacy. For long-term storage, consider using an inert atmosphere (e.g., nitrogen or argon blanket) to minimize potential oxidation.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to reference spectrum
Assay (HPLC)	≥ 98.0 %
Melting Point	75 - 95 °C
Loss on Drying	≤ 0.5 %
Acidity (as H3PO4)	≤ 0.1 %
Solution Color (APHA)	≤ 50
Heavy Metals (as Pb)	≤ 10 ppm

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