In the world of material science, understanding the 'how' behind chemical performance is as important as knowing the 'what'. For businesses relying on the durability and longevity of their polymer and textile products, the role of UV absorbers is critical. NINGBO INNO PHARMCHEM CO.,LTD. is dedicated to illuminating the science behind our advanced chemical solutions, particularly focusing on the effectiveness of UV Absorber UV-366 (CAS 169198-72-5).

The Mechanism of UV Degradation
Ultraviolet (UV) radiation from sunlight is a potent energy source that can initiate photo-oxidation in polymers and textiles. This process involves the absorption of UV photons by polymer chains or chromophores (color-bearing parts of molecules), leading to the formation of reactive species like free radicals. These radicals can then trigger a chain reaction, breaking down the material’s structure. For textiles, this means color fading and fiber weakening; for polymers, it results in chalking, embrittlement, and loss of mechanical properties.

How UV Absorber UV-366 Works: The Benzotriazole Mechanism
UV Absorber UV-366 belongs to the benzotriazole class of UV absorbers. Its efficacy lies in its molecular structure, which is designed to efficiently absorb UV light and dissipate this energy safely. The core mechanism involves:

  1. UV Light Absorption: The molecule possesses conjugated pi-electron systems within its benzotriazole and hydroxyphenyl components. These systems are capable of absorbing UV photons, particularly in the UV-A and UV-B ranges, which are most damaging to materials.
  2. Intramolecular Proton Transfer (Excited State Intramolecular Proton Transfer - ESIPT): This is the key to the photostability of benzotriazole UV absorbers like UV-366. Upon absorbing a UV photon, the molecule enters an excited state. In this excited state, a proton (H+) is rapidly transferred from the hydroxyl (-OH) group to the nearby nitrogen atom in the benzotriazole ring.
  3. Tautomerization and Energy Dissipation: This proton transfer leads to the formation of a keto tautomer. The molecule then returns to its ground state through non-radiative decay pathways, essentially releasing the absorbed UV energy as harmless thermal energy (heat). Importantly, this cycle is highly efficient and repeatable, allowing a single UV-366 molecule to absorb and dissipate numerous UV photons without degrading itself significantly.
  4. High Molar Extinction Coefficient: The specific arrangement of functional groups and the electronic structure of UV-366 result in a high molar extinction coefficient. This means it absorbs UV light more strongly per molecule than many other UV absorbers, providing superior protection even at lower concentrations.

Why UV-366 Excels in Performance
The scientific basis of UV-366’s effectiveness is further amplified by its physical and chemical properties: its high molecular weight and resistance to extraction ensure it remains within the material matrix, providing long-lasting protection. Its non-volatility prevents loss during high-temperature processing, a common issue with less robust UV absorbers. For textile applications, its strong adsorptivity to fibers ensures that the protection is deeply integrated into the fabric structure.

Partner with NINGBO INNO PHARMCHEM CO.,LTD.
Understanding the science empowers better material choices. If you are looking to buy UV-366 UV absorber and want to leverage its advanced protection mechanism for your polymers, textiles, or coatings, we are your trusted supplier. We offer high-quality products, competitive UV absorber prices, and expert technical support from China. Contact us today to learn more about the scientific advantages of UV-366 and how it can protect your valuable products.