Molecular weight:        425 g/mol
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Application:
Thorb® 1577 applications include polyalkene terephthalates and naphthalates, linear and branched polycarbonates, modified polyphenylene ether compounds, and various high performance plastics.

The use of Thorb® 1577 is indicated in polymer blends and alloys, such as PC/ABS, PC/PBT, PPE/IPS, PPE/PA and copolymers as well as in reinforced, filled and/or flame retarded compounds, which can be transparent, translucent and/or pigmented. Its very low tendency to chelate allows Thorb® 1577 formulations in polymers containing catalyst residues.
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Features/Benefits 
Thorb® 1577 is particularly suitable for processing and aging conditions where high loadings, low volatility and good compatibility are required. Such requirements are especially critical for complex moldings, fibers, plain and corrugated sheets, thin films, co-injected or co-extruded semi-finished parts.
Depending on equipment, processing conditions, and polymer types, Thorb® 1577 allows direct two-layer co-extrusion of sheets without the use of a neutral third top layer to prevent sublimation and/or deposits generated by the thin, highly UVA loaded cap layer. Moreover, its very high UV screen activity allows the use of lower concentrations than with traditional UV absorbers. This may be of particular importance when using Thorb® 1577 in high concentration applications.
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Product Forms:     Thorb® 1577 yellowish, free-flowing powder
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Guidelines for use   
Thorb® 1577 (0.2 - 6 % by weight) can be readily incorporated into the polymer by using conventional techniques, e.g. powder, solution, or melt blending. Thorb® 1577 can be used alone or in combination with other functional additives such as antioxidants (hindered phenols, phosphites) and HALS light stabilizers, where often a synergistic performance is observed. Extensive performance data are available in many of the substrates listed above.
 
Absorbance spectrum (10 mg/l, Chloroform)  
Thorb® 1577 exhibits strong absorbance in the 300-400 nm region and minimal absorbance in the visible region (> 400 nm) of the spectrum. The absorption maxima are at 274 nm and 341 nm (epsilon = 22,000 l/mol.cm) in chloroform solution.
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