Antioxidants are used to protect polymers from degradation, both during processing (short term stabilization) and during use (long term stabilization). Polymer degradation generally results in gel formation and changing melt flow index, loss of mechanical and a esthetical properties (crazing, gloss reduction, chalking), and discoloration. Plastics generally ages rapidly under the effects of light, oxygen and heat leading to:
- Loss of strength, stiffness of flexibility
- Discoloration
- Scratching and loss of gloss