Antioxidant 168: A Critical Solution for Polymer Processing Stability
Modern plastics are expected to perform under increasingly demanding conditions. Whether used in automotive parts, packaging films, electrical components, or construction materials, polymers must withstand heat, oxygen exposure, and long-term aging without losing their mechanical properties.
One of the most effective additives used to protect polymers during processing is Antioxidant 168, a phosphite-based secondary antioxidant widely recognized for its excellent thermal stabilization performance. Antioxidant 168 helps prevent polymer degradation during high-temperature manufacturing processes such as extrusion, injection molding, blow molding, and compounding.
This article explores the properties, functions, applications, and benefits of Antioxidant 168 and explains why it remains one of the most important stabilizers in the plastics industry.
What Is Antioxidant 168?
Antioxidant 168, chemically known as Tris(2,4-di-tert-butylphenyl) phosphite, is a highly efficient phosphite ester antioxidant designed primarily as a processing stabilizer for polymers. It reacts rapidly with hydroperoxides generated during thermal processing, converting them into non-reactive compounds before they can initiate polymer degradation.
Basic Product Information
| Property | Value |
|---|---|
| Chemical Name | Tris(2,4-di-tert-butylphenyl) phosphite |
| CAS Number | 31570-04-4 |
| Molecular Formula | C42H63O3P |
| Molecular Weight | 646-647 |
| Appearance | White crystalline powder |
| Melting Point | 183-187°C |
Antioxidant 168 is widely used across the plastics industry because of its:
- Excellent thermal stability
- Low volatility
- High hydrolysis resistance
- Non-discoloring characteristics
- Strong compatibility with many polymers
- Synergistic performance with phenolic antioxidants
Why Do Polymers Need Antioxidants?
During polymer processing, materials are exposed to elevated temperatures and oxygen. This combination can trigger oxidation reactions that lead to:
- Molecular chain scission
- Loss of mechanical strength
- Yellowing and discoloration
- Reduced impact resistance
- Lower product lifespan
Without proper stabilization, these effects can significantly reduce product quality and increase manufacturing waste. Antioxidants are therefore essential additives that protect polymers from thermal oxidative degradation during both processing and end-use service life.
How Antioxidant 168 Works
Antioxidant 168 functions as a secondary antioxidant.
Unlike primary antioxidants that neutralize free radicals, Antioxidant 168 targets hydroperoxides formed during oxidation. These hydroperoxides are unstable intermediates that can decompose into highly reactive radicals capable of accelerating polymer degradation.
Antioxidant 168 decomposes hydroperoxides into stable, non-destructive compounds, interrupting the oxidation cycle before severe degradation occurs.
Key Benefits of This Mechanism
- Improved melt stability
- Reduced viscosity changes during processing
- Enhanced color retention
- Lower gel formation
- Better long-term durability
Synergistic Effect with Primary Antioxidants
One reason Antioxidant 168 has become an industry standard is its excellent synergy with hindered phenolic antioxidants.
Common combinations include:
In these systems:
- Phenolic antioxidants eliminate free radicals.
- Antioxidant 168 decomposes hydroperoxides.
Together they provide significantly better protection than either additive alone. This dual-action stabilization system is commonly used in polyolefins, engineering plastics, and elastomers.
Major Advantages of Antioxidant 168
1. Outstanding Processing Stability
High-temperature polymer processing can rapidly generate oxidative degradation products. Antioxidant 168 protects the polymer melt during extrusion, compounding, and molding operations.
Benefits include:
- Consistent processing performance
- Reduced polymer breakdown
- Improved manufacturing efficiency
2. Excellent Color Protection
Oxidative degradation often causes yellowing or discoloration in plastic products.
Antioxidant 168 helps maintain:
- Bright colors
- Transparency
- Surface appearance
This is particularly important in packaging, consumer products, and transparent engineering plastics.
3. Low Volatility
Because of its low volatility, Antioxidant 168 remains effective even under demanding processing temperatures.
Advantages include:
- Reduced additive loss
- Consistent stabilization
- Better long-term performance
4. Hydrolytic Stability
Modern polymer applications often encounter humid or challenging environments.
Antioxidant 168 demonstrates excellent resistance to hydrolysis, making it suitable for many engineering and outdoor applications.
Applications of Antioxidant 168
Polyolefins (PE and PP)
Polyethylene and polypropylene are among the largest consumers of Antioxidant 168 worldwide.
Applications include:
- Packaging films
- Pipes
- Containers
- Household products
- Injection molded components
The additive helps preserve polymer integrity during high-speed processing.
Engineering Plastics
Antioxidant 168 is widely used in:
- Polycarbonate (PC)
- Polyamide (PA)
- ABS
- POM
- PET
- PBT
- PMMA
These materials often require superior thermal stability and color retention during manufacturing.
Elastomers and Rubber
The product is also suitable for:
- EPDM
- SBR
- SEBS
- Butyl Rubber
- Other synthetic elastomers
It helps improve heat aging resistance and processing stability.
Adhesives and Coatings
In adhesive and coating formulations, Antioxidant 168 contributes to:
- Thermal resistance
- Storage stability
- Long-term performance
These benefits are particularly valuable in industrial and automotive applications.
Recommended Dosage
The recommended dosage depends on polymer type, processing conditions, and performance requirements.
Typical use levels range from:
0.05% – 0.20%
For demanding applications, Antioxidant 168 is often combined with primary antioxidants to achieve optimal stabilization performance. Product-specific testing is recommended to determine the most effective formulation.
Why Choose Ecochem Antioxidant 168?
At Ecochem China, we provide high-quality polymer additives designed to improve processing efficiency and extend product lifespan.
Our Antioxidant 168 offers:
- High purity and consistent quality
- Excellent thermal stabilization performance
- Reliable hydrolysis resistance
- Compatibility with a wide range of polymers
- Global export support
- Technical application assistance
Whether you manufacture packaging materials, engineering plastics, automotive components, elastomers, or specialty compounds, Ecochem can provide stabilization solutions tailored to your requirements.
Conclusion
Antioxidant 168 remains one of the most important processing stabilizers used in modern polymer manufacturing. Its ability to decompose hydroperoxides, prevent thermal degradation, and work synergistically with primary antioxidants makes it indispensable in plastics, elastomers, adhesives, and engineering materials.
By incorporating Antioxidant 168 into polymer formulations, manufacturers can improve processing stability, preserve product appearance, extend service life, and achieve superior overall performance.
For technical support, samples, or pricing information, contact Ecochem today.
Contact Us
Ecochem China
Website: www.ecochemchina.com
Email: info@ecochemchina.com
WhatsApp: +86-18921308539
