What is the main purpose of antioxidants in polymers?

The primary role of antioxidants in polymers is to prevent oxidative degradation. Polymers are often exposed to heat, light, and oxygen during processing and end-use, which can lead to the breakdown of molecular chains and deterioration of material properties. Oxidative degradation can manifest as discoloration, loss of strength, and brittleness, ultimately compromising the performance and longevity of the polymer material.

Antioxidants work by scavenging free radicals and reactive oxygen species that contribute to oxidative reactions. By effectively neutralizing these harmful agents, antioxidants help maintain the structural integrity and performance of polymers over time. This is particularly crucial for applications where durability and stability are essential, such as in automotive, construction, and consumer goods.

The other options may relate to different enhancements or characteristics of polymers, but they do not address the critical function of antioxidants as effectively as preventing oxidative degradation does. Enhancing color stability or improving moldability might be relevant to certain additives or processing aids, while increasing flexibility is more closely related to the choice of polymer type or plasticizers rather than antioxidants specifically.