costabilizers

Costabilizers are additives used in polymer formulations to enhance stability and performance by working in concert with primary stabilizers. They are not primary stabilizers themselves but help extend the effectiveness of antioxidants, UV absorbers, or processing aids, often enabling a lower total load of stabilizers and reducing overall costs. In some contexts they are referred to as co-stabilizers.

They function by scavenging reactive radicals, decomposing hydroperoxides, chelating trace metals, or absorbing ultraviolet radiation, thereby reducing chain scission and color formation during processing and throughout the product’s service life. The result is improved thermal, oxidative, and color stability without excessive additive content.

Common types include processing stabilizers such as phosphites used with polyolefins, metal soaps, and certain esters. In PVC and other resins, costabilizers are selected to complement primary stabilizers and suppress degradation during extrusion and molding. The choice depends on the resin system, processing conditions, and desired balance of performance and cost.

Applications span polyolefins, PVC, and engineering plastics in packaging, automotive parts, and consumer products. Design considerations include compatibility with the resin, potential migration, regulatory compliance, and the overall cost benefit of using costabilizers versus higher levels of primary stabilizers. See also related stabilization concepts such as antioxidants, UV stabilizers, HALS, and co-stabilizers.