Ultraviolet Protective Agents

Ultraviolet protective agents are used either to protect the plastic itself from strong sources of ultraviolet light such as sunlight and also to protect the packaged foodstuff from such radiation and possibly from the effects of strong lighting when on display in supermarkets. 

An instance where such protection is required is in the packaging of vitamin C containing cordials where, without protection, ultraviolet light would produce severe degradation of the vitamin. 

Ultraviolet protective agents fall into two categories, those operating as UV screens, and those which operate by interfering with a degradation chain reaction in the polymer that has been initiated or catalysed by the radiation. 

Two commonly used UV stabilisers are (2,2-(hydroxyl-3-tert-butyl-5-methylphenyl)5-chlorobenzotriazole and 2-hydroxy-4- -octyloxy-benzophenone. 

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Ultraviolet protective agents and ultraviolet degradation inhibitors... 

Both the acetal and the aldehyde can be used as intermediates for crop protection agents, fragrances, plating additives, ultraviolet (UV) absorbers, optical brighteneres, and other applications. 

Feruloyl esterases show intriguing differences in substrate specificity and sequence structure. The main reason for the recent increase in interest in these enzymes is their potential application in the production of ferulic acid. Ferulic acid is an important precursor in the flavor industry (77) and has multiple uses as an ultraviolet light protection agent in sun creams and cosmetics (72) by suppressing inflammatory responses and skin tumor development (75). Feruloyl esterases can also be used to selectively remove ferulic acid from agro-industrial waste products on an industrial scale 74). Ferulic acid is thought to be involved... 

To the LC polyester composition additives can also be used in the form of antioxidants and heat stabilizers such as a hindered phenol, hydroquinones, phosphites etc. Another additives, also added as required, can be mentioned as, ultraviolet absorber (resorcinol, salicylate etc.), color protecting agent (phosphate, hypo-phosphite etc.), lubricant and mold lubricant (stearyl alcohol, stea-ramide etc.) [137]. 

Salicylic acid is a beta hydroxy acid. Glycolic acid is an alpha hydroxy acid, as are lactic acid, citric acid, and many others. Hydroxy acids are compounds that are both alcohols and acids at the same time. Hydroxy acids are used as chemical peeling agents. Alpha hydroxy acids can make the skin more sensitive to ultraviolet light by removing the skin s protective outer layers. Some alpha hydroxy acids ... 

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