Light stability assessment

Biocides. The attack of fungi on the several components of a vinyl formulation may manifest itself as an unsightly growth looking much like dirt or may result in the formation of discolored areas (yellow, pink, blue, clear) on the finished goods. Outdoor exposure, indoor exposure in humid atmosphere, soil burial or contact, and electrical insulation compounds are typical areas where biocide addition is indicated. Since most commercial biocides are heavy metal derivatives, care must be taken to assess their effect on heat and light stability and compatibility with the vinyl system in which they are used. 

Details DIBP is one of the rare odourless plasticisers with excellent heat/light stabilities, and it is inexpensive. DIBP is a commonly used as a plasticiser for cellulose nitrate production. DIBP has not yet undergone an EU classification and labelling assessment and it is very unlikely that it has any toxicological effects. Since it is not known for sure, its toxicology information is not given here (http //w w w. dibp-facts.com/index.asp page=3). 

In order to assess the efficiency of a light stabilizer in its coupling with a phenolic antioxidant, multifunctional hindered amine light stabilizer or some complexes of tetramethylpiperidine with nickel were synthesized [48]. These products were successfiiUy used for the stabUization of monofilament polypropylene and the usage range was expanded to low density polyethylene. For the PVC stabilization, some stilbene compounds such as 4-chloro-a-cyan-3-methyl-stilben (9) were also efficiently used [49]. 

A number of factors must be assessed in choosing a plasticiser for a given application. These include solvating power, efficiency, compatibility, volatility, extraction and migration resistance, heat and light stability, flame retard-... 

The purpose of stability testing is to assess the effects of temperature, humidity, light, and other environmental factors on the quality of a drug substance or product. The data produced are used to establish storage conditions, retest periods, shelf loss, and to justify overages included in products for stability reasons. The most useful equation relating temperature and reaction rate is the Arrhenius equation. This equation (27) may be integrated and rewritten as Eqs. (31) and (32). 

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