Description

Tetraphenyl Dipropyleneglycol Diphosphite is a high-performance organophosphite antioxidant and stabilizer widely used in polymer processing. This compound is valued for its exceptional ability to prevent thermal and oxidative degradation, thereby extending the service life and maintaining the color of finished polymeric materials. It is an essential additive for manufacturers in the plastics, synthetic fiber, and specialty resin industries seeking to enhance product durability and performance under demanding conditions.

Application

• Polymer Stabilization: Primary function as a highly effective processing stabilizer and secondary antioxidant in polyolefins (PP, PE), polyesters (PET, PBT), and engineering plastics.
• Color Retention: Prevents yellowing and discoloration in polymers during high-temperature processing and long-term aging, critical for clear and white applications.
• Synergistic Systems: Used in combination with primary phenolic antioxidants to create robust stabilization packages that offer superior protection against thermal oxidation.
• Fiber and Film Production: Protects synthetic fibers and thin films during melt spinning and extrusion processes, maintaining tensile strength and clarity.
• Adhesives and Coatings: Enhances the thermal stability of hot-melt adhesives and polymer-based coating formulations.
• Recycling Streams: Helps stabilize post-consumer and post-industrial recycled polymers, restoring and maintaining their performance properties.

Basic Information

Product Name	Tetraphenyl Dipropyleneglycol Diphosphite
CAS No.	80584-85-6
Molecular Formula	C36H34O6P2
Molecular Weight	624.59 g/mol
Synonyms	Dipropylene glycol tetraphenyl diphosphite; Bis(dipropylene glycol) tetraphenyl diphosphite; Phosphorous acid, cyclic tetraphenyl ester with dipropylene glycol; Weston 618; Antioxidant 618; Polygard P; Tetraphenyl bis(propylene glycol) diphosphite; 3,9-Bis(2,4-di-tert-butylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (related structural analog)
EINECS	279-562-8

Quality Control

Our Tetraphenyl Dipropyleneglycol Diphosphite is manufactured under strict quality management systems to ensure batch-to-batch consistency and high performance. Each lot is subjected to rigorous analytical testing, including assay, color, and acidity control, to meet precise industry specifications. A comprehensive Certificate of Analysis (COA) detailing all quality parameters is provided with every shipment to support your quality assurance protocols.

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). This product is hygroscopic (moisture-sensitive); the container must be kept tightly sealed after initial opening to prevent degradation from atmospheric moisture.

Specification

Item	Specification
Appearance	White to off-white crystalline powder or flakes
Identification (IR)	Conforms
Assay (HPLC)	≥ 98.0 %
Acidity (as H3PO4)	≤ 0.1 %
Color (Pt-Co)	≤ 50
Melting Point	90 - 110 °C
Phosphorus Content	9.5 - 10.0 %
Loss on Drying	≤ 0.5 %

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