Antioxidant

material

Chemical additives that prevent polymer degradation by neutralizing free radicals and reactive oxygen species during processing and service life, maintaining material properties.

In Simple Terms

Antioxidants are protective chemicals added to plastic resins to prevent degradation from heat, oxygen, and UV exposure. They act like preservatives, keeping the plastic from breaking down and losing its strength, color, and flexibility over time.

Why It Matters

Antioxidants are critical for maintaining resin quality during high-temperature processing and extending product lifespan. Without proper antioxidation, polymers suffer chain scission, discoloration, and property loss that can render materials unusable.

Technical Details

Primary antioxidants (phenolic, aminic) donate hydrogen atoms to neutralize polymer radicals, while secondary antioxidants (phosphites, thioesters) decompose hydroperoxides. Typical loading levels range from 0.05-0.5%. Synergistic combinations provide optimal protection across processing temperatures of 200-300°C.

Real-World Examples

PP homopolymer stabilization

Irganox 1010 (phenolic antioxidant) added at 0.1% prevents chain scission during extrusion at 230°C, maintaining melt flow rate within specification

HDPE film production

Combination of Irganox 1076 and Irgafos 168 prevents gel formation and maintains optical properties during blown film processing

Resin storage protection

BHT antioxidant in virgin PET prevents intrinsic viscosity drop during warehouse storage, ensuring consistent bottle-grade performance