UVstabilisering

UVstabilisering refers to the measures used to limit degradation of polymers and coatings caused by ultraviolet light. Ultraviolet exposure can initiate photochemical reactions that lead to chain scission, oxidation, discoloration, and embrittlement, diminishing mechanical properties and appearance. Stabilization is achieved primarily through additive systems that absorb UV energy or quench reactive species, thereby slowing or preventing damage.

Two main classes of stabilizers are widely used. UV absorbers capture UV photons and convert the energy to harmless heat, protecting the polymer backbone. Hindered amine light stabilizers (HALS) do not absorb light themselves but scavenge free radicals generated during photolysis, interrupting degradation chains. These stabilizers are often used in combination to provide complementary protection. In some formulations, antioxidants are included to improve long-term stability, particularly at elevated temperatures.

Applications span a broad range of polymers and coatings. Common plastics such as polyolefins (PE, PP), polyvinyl chloride (PVC), and PET, as well as exterior coatings and wood-plastic composites, rely on UVstabilisering to maintain color, clarity, and mechanical performance. The choice of stabilizers depends on the polymer, processing conditions, color requirements, and potential interactions with other additives. Migration or blooming of stabilizers can affect appearance and recycling streams.

Testing and standards for UVstabilisering typically involve accelerated weathering or solar-simulation tests (e.g., QUV, ISO 4892, or ASTM G53/G154) to evaluate color retention, gloss, and mechanical properties over time. Service life is influenced by exposure environment, stabilizer type and concentration, pigment load, and overall formulation.