Stabilizers For Polymers

Stabilizers for polymers are used directly or by combinations to prevent the various effects such as oxidation, chain scission and uncontrolled recombinations and cross-linking reactions that are caused by photo-oxidation of polymers. Polymers are considered to get weathered due to the direct or indirect impact of heat and ultraviolet light. The effectiveness of the stabilizers against weathering depends on solubility, ability to stabilize in different polymer matrix, the distribution in matrix, evaporation loss during processing and use. The effect on the viscosity is also an important concern for processing.

Heat stabilizers are mainly used for construction products made of polyvinyl chloride, for instance window profiles, pipes and cable ducts. Light stabilizers, for instance HALS, are especially needed for polypropylene and polyethylene. The environmental impact of stabilizers for polymers can be problematic because of heavy metal content. In Europe lead stabilizers are increasingly replaced by other types, for example calcium-zinc stabilizers.