Antioxidant 245 CAS 36443-68-2

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CAS:36443-68-2

Molecular Formula:C34H50O8

Molecular Weight:586.77

EINECS:253-039-2

Antioxidant 245 is a hindered phenolic antioxidant that prevents thermal oxygen degradation of materials during synthesis, processing and final use. Antioxidant 245 is odorless, low volatility, and has good color stability and extraction resistance. Antioxidant 245 is a highly effective asymmetric hindered phenol antioxidant, which is characterized by high antioxidant efficiency, low volatility and good oxidation resistance.

Item	Specification
Melting point	79-81℃
Boiling point	602.88°C (rough estimate)
Density	1.0397 (rough estimate)
Acidity coefficient (pKa)	11.44±0.25(Predicted)
Refractive index	1.6000 (estimate)
Flash point	>150 °C
LogP	4.7 at 23℃

Antioxidant 245 is widely used in ABS, HIPS, MBS, SBS, and styrene copolymer systems where color stability and heat aging resistance are critical. It helps reduce polymer degradation during extrusion and injection molding while maintaining gloss and impact strength.

It is especially suitable for:

appliance housings
office equipment plastics
TV frames
consumer electronics
modified styrenic compounds

For enhanced melt-processing stabilization in styrenic resins, it can be formulated together with Antioxidant 168.

2. TPU & Polyurethane Elastomers

Antioxidant 245 performs very well in TPU, polyurethane adhesives, RIM systems, and spandex elastomers because of its low volatility and excellent extraction resistance. It helps reduce yellowing and improves long-term thermal stability in flexible polyurethane materials.

3. POM & Engineering Thermoplastics

The product is commonly used in POM copolymers, polyamide, thermoplastic polyester, and engineering plastics exposed to repeated thermal processing conditions. It helps minimize molecular chain scission and maintains mechanical properties under heat aging environments.

In high-temperature engineering resin systems, Antioxidant 245 can also work synergistically with Antioxidant 1098 for enhanced long-term stabilization.

4. PVC Polymerization & Processing

Antioxidant 245 is effective as a chain terminator during PVC polymerization and can improve processing stability in rigid and flexible PVC compounds. It helps suppress thermal oxidation during high-temperature manufacturing.

5. Weather-Resistant Polymer Systems

When used together with light stabilizers and phosphite antioxidants, Antioxidant 245 can improve weather resistance and outdoor durability in polymer applications exposed to heat and oxygen.

Explore polymer stabilization solutions for engineering thermoplastics, TPU systems, and modified styrenic resins at Unisunchem.

High-efficiency asymmetric hindered phenolic antioxidant
Excellent color retention during high-temperature processing
Low volatility and low odor properties
Outstanding extraction resistance in polyurethane and elastomer systems
Effective long-term thermo-oxidative stabilization
Particularly suitable for ABS, HIPS, TPU, POM, and PVC applications
Helps maintain polymer impact strength and gloss retention
Strong synergistic effect with phosphites and thioester antioxidants
Good compatibility with engineering thermoplastics and elastomers
Stable industrial supply from Unisunchem

25kg/drum or according to customer requirements.

AQ

Q1: Why is Antioxidant 245 commonly used in ABS and HIPS?

ABS and HIPS are sensitive to thermal oxidation during extrusion and injection molding. Antioxidant 245 helps maintain impact strength, surface gloss, and color stability while reducing degradation caused by heat processing.

Q2: Is Antioxidant 245 suitable for TPU applications?

Yes. Antioxidant 245 is widely used in TPU and polyurethane elastomers because of its low volatility and excellent extraction resistance, which help improve long-term heat aging performance.

Q3: What makes Antioxidant 245 different from Antioxidant 1076?

Antioxidant 1076 is mainly used in polyolefins and flexible packaging systems, while Antioxidant 245 is more widely applied in styrenic polymers, TPU, engineering plastics, and PVC polymerization systems.

Q4: Can Antioxidant 245 improve weather resistance?

Yes. When combined with light stabilizers and phosphite antioxidants, Antioxidant 245 can help improve long-term outdoor durability and reduce oxidative discoloration in weather-exposed polymer products.

Q5: Why is Antioxidant 245 considered a low-volatility antioxidant?

Its molecular structure gives it excellent permanence and low evaporation loss during high-temperature processing, making it especially suitable for engineering plastics and polyurethane systems requiring long-term stability.