June 30, 2026

What Is Antioxidant 168 Used For? Applications, Specs and Sourcing

Home | Topics | 

Chemical Identity

  • Chemical name: Tris(2,4-di-tert-butylphenyl) phosphite
  • CAS number: 31570-04-4
  • Molecular weight: 647.0 g/mol
  • Appearance: White crystalline powder or granules
  • Melting point: 183–187°C
  • Commercial equivalents: Irgafos 168, Doverphos S-680

How It Works

As a secondary antioxidant, Antioxidant 168 decomposes hydroperoxides formed during melt processing, converting them to stable alcohols before they generate radicals. This protects the polymer during high-temperature extrusion and injection molding, preserving melt flow, color, and molecular weight.

Applications

  • Polypropylene (PP): Standard stabilization partner with Antioxidant 1010 or 1076
  • Polyethylene (PE): Critical in HDPE/LLDPE pipe compounds and film
  • ABS, HIPS, and styrenic polymers: Color and MFI stabilization
  • Engineering plastics (PA, PBT, PET): High-temperature processing stability
  • Thermoplastic elastomers (TPE, TPU): Color retention
  • Adhesives and hot-melt systems: Processing viscosity stability

Typical Dosage

Combined loading with Antioxidant 1010 at 1:1 or 1:2 ratio: 0.1–0.3% in polyolefins; 0.2–0.5% in engineering plastics.

FAQ

Is Antioxidant 168 the same as Irgafos 168?
Chemically identical (CAS 31570-04-4). Irgafos 168 is the BASF brand; Antioxidant 168 is the generic designation used by Chinese manufacturers.

Is it food-contact approved?
Yes. Listed in FDA 21 CFR §178.2010 and EU Plastics Regulation 10/2011. Specific migration limits apply.

Contact SUNCHEM

Get pricing, samples, and COA for Antioxidant 168. Contact SUNCHEM for export documentation and technical support.

Article written by market
magnifier