UVsprickor

UVsprickor, also known as ultraviolet cracks, are a phenomenon observed in certain materials when exposed to ultraviolet radiation over time. This type of degradation is most commonly associated with polymers and plastics, where UV light can initiate photochemical reactions that break down the molecular bonds within the material. This breakdown leads to a loss of mechanical strength, flexibility, and can manifest as surface crazing or fine fissures.

The process begins with the absorption of UV photons by the polymer chains. These high-energy photons can excite electrons, leading to bond cleavage and the formation of free radicals. These free radicals can then react with oxygen, accelerating the degradation process through photo-oxidation. The resulting changes in the material's chemical structure can lead to embrittlement and the formation of visible cracks.

The severity of UVsprickor depends on several factors, including the type of material, the intensity and duration of UV exposure, and the presence of other environmental factors such as heat and humidity. Stabilizers, such as UV absorbers and hindered amine light stabilizers (HALS), are often added to polymers to mitigate this degradation and extend the lifespan of products exposed to sunlight. Examples of materials susceptible to UVsprickor include outdoor furniture, automotive components, and certain types of coatings and films.