The ultraviolet absorbent includs aromatic compounds of benzene ring which can absorb ultraviolet ray. Benzene ring absorb ultraviolet rays energy via resonant interaction, and transform it into thermal energy or harmless luminous energy which will be released, after that, the molecular structure of aromatic compounds of benzene ring returned to its original condition. The ultraviolet absorbent repeates this same procedure every minute per second without harming itself. Different ultraviolet absorbent absorbs ultraviolet ray with different wave length, and the wave length of harmful ultraviolet ray that degrade polymer is different, so the choice of aromatic compounds of benzene ring should be considered based on the types of polymer.
The silk plants is protected from ultraviolet ray because ultraviolet absorbent was added in its materials, with the absorbent, imitation plants items can keep its original color for 3 to 5 year till all absorbent exhaust itself. While those fake plants items without absorbent can keep its color only for 1 year. Now do you know how artificial plants be protected from ultraviolet ray?
