Sulfur Antioxidants vs Phenolic Antioxidants: Key Differences

Chemical Classification

Phenolic Antioxidants (Primary)

• Antioxydant 1010 (CAS 6683-19-8): High MW tetrafunctional, polyolefin standard
• Antioxydant 1076 (CAS 2082-79-3): Monofunctional, cost-effective
• Antioxydant 1098 (CAS 23128-74-7): Preferred for polyamides

Sulfur (Thioester) Antioxydants (Secondary)

• DLTDP (CAS 123-28-4): C12 chains, standard polyolefin grade
• DSTDP (CAS 693-36-7): C18 chains, high-temperature preferred

Mechanism Comparison

Phenolic antioxidants scavenge free radicals directly — donating hydrogen to peroxy radicals to break chain propagation. They are primary antioxidants.

Thioester antioxidants decompose hydroperoxides (ROOH → ROH), preventing reinitiation of the radical chain. They are secondary antioxidants.

Application Selection

• Choose phenolic-dominant system when service-life thermal aging is the primary concern
• Include thioester when long-term thermal stability is required, or for cost optimization
• For processing temperatures >220°C, prefer phosphite (Antioxydant 168) over thioester as secondary
• For food contact, verify specific regulatory clearance for each grade

Contact SUNCHEM

Both phenolic and thioester antioxidant grades available from SUNCHEM with full technical documentation. Contactez-nous for pricing and samples.