Studies of plastics degradation show that small amounts of impurities or chromophores are sufficient to induce photo-oxidative degradation even in the absence of appreciable UV absorption by the polymer.
The first and most obvious means of protecting a polymer against UV light is based on the prevention of UV light absorption or the reduction of the amount of light absorbed by the chromophores.
The second possibility is the reduction of the initiation rate through deactivation of the excited states of the chromophoric groups.
A third possibility involves intervention in the photo-oxidative degradation process that arises when the chain branching
step is considered; in this case, UV protection implies the transformation of hydroperoxides into more stable compounds, without generation of free radicals, before the hydroperoxides undergo photolytic cleavage. This, of course, means again reducing the initiation rate and is sometimes considered the most important step of UV stabilization. In addition to that, the deactivation or complexing of chromophoric groups other than hydroperoxides may be of some importance.
The fourth and last possibility to stop photo-oxidative degradation consists in scavenging the free radicals as soon as possible after their formation, either as alkyl radicals or as peroxy radical.
UV absorbers for plastic mitigate the damaging effects of the sun. Adding these products to a surface preserves the color brilliance and lifespan of ultraviolet-sensitive . Do not confuse UV absorbers with blockers. These do not block ultraviolet light. Instead, UV absorbers sacrifice themselves to preserve the polymers they protect. These products compete with the surface material for the UV radiation from the sun. Because these additives have a proclivity for drawing in ultraviolet rays, they prevent the rays from reaching the substrate. By absorbing sunlight instead of letting it reach the polymer, UV absorbers protect the product plastic.
Because nothing can destroy energy, the radiation the UV absorber takes in must go somewhere. These products typically change the energy from UV radiation into heat. In this manner, these absorbers safely release the UV radiation in a way that does not cause damage to the material they protect.
The amount of UV absorber needed depends on its concentration and the surface’s thickness. The relationship between absorber concentration and surface thickness is not linear. Higher levels reduce effectiveness. Therefore, thicker materials will need higher-than-predicted concentrations. To find the right absorber, formulators need to conduct extensive tests to find the concentration required to prevent photodegradation. Not all products absorb across the full UV wavelength spectrum. Since these products typically absorb UV rays and not visible light, they appear transparent. UV absorbers should not block as many rays to avoid blocking blue light waves, making the material beneath appear yellow.
Any material that requires protection from ultraviolet radiation needs some treatment. UV absorbers have a wide range of materials they can protect. However, not all products in this category have the same efficiency.
UV absorbers work best when used with a thick material because these products rely on depth as part of their effectiveness. Generally, very thin films that need heavy ultraviolet protection would not benefit from UV absorbers as much as they would from another type of light stabilizer or additive. Because UV absorbers vary in their effectiveness depending on thickness, concentration, and formulation, engineers must carefully choose the best absorber for a particular application.
UV absorbers are an ideal first line of defense against ultraviolet radiation damage. Often, manufacturers will use these products in combination with quenchers or light stabilizers for the longest-lasting, most significant benefit. UV absorbers will eventually experience a reduction in their ability to preferentially absorb ultraviolet light. When they do, if the material does not also include another form of damage prevention, it will begin to show photodegradation. To avoid this problem, engineers can incorporate light quenchers or stabilizers into the material or coating, depending on the type of polymer protected.
The use of UV absorbers has increased in plastics application owing to the high demand from industries such as packaging and agricultural films. In addition, the rapidly growing automotive industry is expected to increase the demand for UV absorbers in coatings and adhesives applications. Personal care and printing inks are the other applications which consume UV absorbers.
The UV absorbers market was valued at USD 690.3 Million in 2016 and is projected to reach USD 1,006.4 Million by 2022, at a CAGR of 6.5% from 2017 to 2022. In this study, 2016 has been considered as the base year, and 2017–2022 as the forecast period for estimating the market size of UV absorbers.
UV absorbers are polymer additives that are used to enhance the performance, shelf life, durability, and stability of plastics, polymers, and wood components. These components are used in various applications such as building & construction, packaging, automotive, agriculture, and adhesives & sealants. The growth of the UV absorbers market is primarily driven by the increasing demand from applications such as plastics, coatings, adhesives, and personal care. UV absorbers is also a major type of UV stabilizer used in neutral or transparent applications to provide effective UV resistance for short term exposures. Plastics is considered as one of the major applications for UV absorbers in emerging as well as developed economies.