Why CAS 31570-04-4 Is a Key Thermal Stabilizer for Modern Polymer Applications

Polymers are exposed to heat and oxygen at two stages. The first is during processing, when temperatures rise sharply during extrusion, moulding, and compounding. The second is during the product’s lifetime, when constant exposure to heat, stress, or the environment slowly affects quality. Both conditions can lead to oxidation, colour change, brittleness, and loss of mechanical strength. This is why thermal stabilizers are a vital part of every polymer formulation. Among them, the compound listed under CAS 31570-04-4 has become one of the most reliable choices for manufacturers across industries. 

What CAS 31570-04-4 Is and Why Its Structure Matters

When users look up the CAS 31570-04-4 chemical structure, they see it defined as tris(2,4-di-tert-butylphenyl) phosphite. It is a phosphite antioxidant with a bulky molecular arrangement. This structure helps it stay stable at high temperatures and prevents it from breaking down easily. It appears as a white, free-flowing powder with a melting range of 183 to 186 degrees Celsius and is valued for its non-discolouring behaviour. That is important because many stabilizers change colour under heat, especially in light-coloured products. CAS 31570-04-4 keeps the polymer clear and clean during and after processing. 

How Does Antioxidant 168 Work?

In practice, manufacturers know the compound as Antioxidant 168. Understanding how Antioxidant 168 works helps explain why it performs well in modern applications. When polymers react with oxygen, they form hydroperoxides. These hydroperoxides break polymer chains and cause early degradation. Antioxidant 168 reacts with these hydroperoxides and converts them into safer by-products. This prevents the chain reaction from spreading through the material. 

It also supports the action of primary antioxidants, which handle free radicals. During processing, primary antioxidants get consumed quickly. Antioxidant 168 takes care of hydroperoxides so the primary antioxidant can remain active for long-term protection. The process improves both processing stability and product shelf life. 

Role in the Wider Family of Polymer Stabilizers and Antioxidants

Within the category of polymer stabilizers and antioxidants, Antioxidant 168 is known as a secondary antioxidant or processing stabilizer. It is rarely used alone. Most manufacturers pair it with a phenolic primary antioxidant to build a complete stabilizer package. The phenolic antioxidant works on free radicals, while Antioxidant 168 handles hydroperoxides. This teamwork reduces polymer breakdown, keeps physical strength intact, and controls changes in appearance. 

Why It Performs Well Under Processing Heat

Polymer processing can involve high temperatures, long residence time, and exposure to oxygen. Under these conditions, many stabilizers degrade or lose strength. CAS 31570-04-4 is valued for its thermal stability. It handles the heat that occurs during extrusion, injection moulding, film blowing, and compounding. It is also hydrolytically stable, which means it does not break down in humid conditions or in processes where moisture is present. 

Another advantage is its non-discolouring behaviour. This quality makes it suitable for applications where clarity, brightness, or consistency of colour are critical. 

Key Applications as a Thermal Oxidation Stabilizer for Plastics

As a strong thermal oxidation stabilizer for plastics, Antioxidant 168 is used across many polymer systems. Some of the most common applications include: 

• Polypropylene and polyethylene used in films, moulded items, and houseware 

• PVC formulations that require colour stability under heat 

• Polystyrene and styrenic blends used in consumer goods and packaging 

• Masterbatches where the stabilizer must not affect pigment strength 

• Rubber compounds that need to maintain elasticity under temperature stress 

• Adhesives, lubricants, and coatings that require long-term heat resistance 

In each of these materials, the stabilizer helps prevent chain scission, cross-linking, surface dullness, and mechanical wear. 

Dosage, Handling, and Practical Use

Most processors use Antioxidant 168 in the range of 0.1 to 1 percent, depending on the polymer and the stabilizer combination. The exact level is usually decided after lab testing or pilot trials. It is available in powder and granule forms. Good storage practices are important because stable packaging maintains purity and ensures consistent performance. Certifications such as REACH compliance and detailed data sheets help manufacturers meet regulatory and quality standards. 

The Real Value It Brings to Manufacturers

The strength of Antioxidant 168 is not limited to one property. It offers a balanced combination of heat stability, colour protection, and compatibility with primary antioxidants. This reduces production defects, lowers reprocessing requirements, and improves the consistency of the final product. For many manufacturers, it becomes a dependable part of the formulation because it works across a wide range of processing conditions and polymer types. 

Smarter Stabilization for Today’s Polymer Needs

CAS 31570-04-4 has become a core ingredient in modern stabilizer systems because it protects polymers during both processing and long-term use. Its ability to neutralise hydroperoxides, support primary antioxidants, maintain colour, and stay stable under heat makes it one of the most practical choices for high-performance plastics. 

Vinati Organics manufactures this phosphite stabilizer under the name Veenox 168. The product is REACH certified, supplied in powder and granule forms, and tested for consistent quality. With a strong focus on research and reliability, Vinati offers Veenox 168 as a dependable choice for manufacturers who want long-lasting protection for their polymers. 

Explore how our high-quality CAS 31570-04-4 can support your polymer projects.