Ultraviolet absorber, Tinuvin

Effect of well-known industrial ultraviolet absorbers of Tinuvine and 2-oxy-4-methoxybenzophenone type, that were not inhibitors of radical processes, was investigated for comparison [162]. Being measured values of the rate of acetic acid accumulation were obtained with regard to corrections for shielding. 

Hydroxy-4 -methylphenyl) benzotria-zole ( Tinuvin P ) n. A non-toxic crystalline powder with high thermal stability, an ultraviolet absorber for polystyrene, acrylics, PVC, polyesters, and polycarbonates. 

The response of polyurethanes to thermally activated autoxidation depends upon polymer structure. In general, polyurethane degradation by this mechanism is suppressed by the addition of antioxidant to the polymer. Ultraviolet initiated autoxidation is suppressed by a suitable screen (e.g. carbon black, titanium dioxide) or a combination of antioxidant and ultraviolet absorber. Irganox 1010 and Tinuvin P (Ciba-Geigy) are particularly suitable antioxidant and ultraviolet absorbers, respectively, for polyurethanes. Polyurethane structures with enhanced resistance to ultraviolet initiated autoxidation may be possible. 

Tinuvin, Ultraviolet absorbers hindered amine light stabilizer, Ciba Specialty Chemicals Corp., Additives Div. 

Thermoplast Dyes, BASF Thermx Copolyester, Eastman Thiokol Tolysulfide, Thikol Tinuvin Ultraviolet absorbers ... 

Methods 17 and 18, respectively, determine Cyasorb UV 531 (2-hydroxy-4-n-octoxybenzophenone) in polyolefins by direct infrared spectroscopy and thin-layer chromatography. Phenolic and organophosphorus type antioxidants do not interfere in these procedures. Method 19 describes an ultraviolet spectroscopic method for the determination of Tinuvin 326 ultraviolet absorber in polypropylene. 

METHOD 19. DETERMINATION OF TINUVIN 326 ULTRAVIOLET ABSORBER IN POLYPROPYLENE. ULTRAVIOLET SPECTROSCOPY. 

This ultraviolet spectroscopic procedure determines Tinuvin 326 ultraviolet absorber in polypropylene in amounts down to 0.02%. 

The photodegradation of synthetic polymers can be considerably reduced upon addition of ultraviolet stabilizers. The UV stabilizers (preferably derivatives of o-hydroxy-benzophenone or of 2-(2 -hydroxys -methylphenyl)benzotriazole (Tinuvin) transform the absorbed light energy into thermal energy thus preventing all sorts of photochemically initiated reactions. For review articles see the papers of Otter-stedt (.l), Heller and Blattmann ( 2, 2), Kloepffer (jl, j ), Gysling (JS) and Trozzolo (19 ) ... 

A number of methods use the UV absorbing properties of the UV stabiliser. For example, Tinuvin 326 can be detected in polypropylene down to 0.02% w/w by using an extraction with chloroform under reflux followed by analysis of the extract using a UV/Vis spectrometer. The ultraviolet absorption peak at 355 nm is used and a calibration curve produced by dissolving known amounts of Tinuvin 326 in chloroform. 

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