Photostability of HDPE Filaments Stabilized with UV Absorbers (UVA) and Light Stabilizers (HALS)

Photostability of HDPE Filaments Stabilized with UV Absorbers (UVA) and Light Stabilizers (HALS)

HDPE monofilaments were photostabilized with hindered amine l ight s tabi l izers (HALS) and UV absorbers at varying stabilizer concentrations. The filaments were assessed for UV resistance by exposure to simulated outdoor weathering conditions in artificial weathering apparatus and testing the exposed samples at regular intervals for retained tensile properties. Films of HDPE of varying thickn...

Investigations on Photostability of UV-Absorbers for Cosmetic Sunscreens

Mechanism of Polymer Stabilization by Hindered-Amine Light Stabilizers (HALS). Model Investigations of the Interaction of Peroxy Radicals with HALS Amines and Amino Ethers

Peroxy radicals, when generated in the presence of hindered-amine light stabilizers (HALS), oxidized HALS to produce nitroxides. This reaction, in addition to the scavenging of alkyl radicals by nitroxides, forms a cycle describing HALS as a class of excellent polymer stabilizers. As model systems for the mechanism of the oxidation of HALS, both alkyl peroxy and acyl peroxy radicals were produc...

Evaluation of the effect of ultraviolet stabilizers on the change in color of a silicone elastomer following aging by three different methods: An in vitro study

Aim and Objective: To compare and evaluate the effect of ultraviolet (UV) stabilizers (UV absorbers [UVA] and hindered amine light stabilizers [HALS]) on the color change of a commonly used silicone elastomer subjected to aging by three different methods. Materials and Methodology: Four groups of 30 samples each were studied; Group A-Control, Group B-Silicone + UVA (Chimassorb 81), Group C-Sili...

Vapour pressures of hydroxybenzophenone UV absorbers

A thermogravimetric method was used to measure the vapour pressures of a series of hydroxybenzophenone UV stabilisers. Enthalpies of vaporisation were determined from the slope of a plot of the logarithm of the vapour pressure against reciprocal absolute temperature. Enthalpies of sublimation were measured either directly by the same method or by summing the enthalpy of vaporisation with the en...