Stability evaluation, polymer weathering

Because weak CL emission often is produced from the oxidation of many solid organic compounds, the measurement of this light emission may be used as an indicator of changes in materials composition due to oxidation processes, and for evaluating stabilizers intended to prevent or retard these oxidative alterations [6], Some examples of materials than can be characterized by CL emission are the polymers that are degraded by weathering, exposure to heat, or exposure to ionizing radiation, or food components that suffer flavor alterations. In this... 

TG-DTA Characterisation of carbon black [149], flammability evaluation [64], polymer degradation studies [65], ageing studies [70-72], product control [77, 81], combustion performance [83], safety evaluation [83], antioxidation activity [68], pyrolysis of rubbers [82], thermal stability [67, 69, 76, 77], interfacial junctions in viscoelastic composites [78], weathering [72], vulcanisation [73], oxidative behaviour [79], materials evaluation [80], failure analyses [81],... 

However, outdoor weathering tests are not quite reproducible due to the instability of the climate. Moreover, they are invariably slow, longer and longer exposure periods being required for the evaluation of new polymers with improved stability. This gradual increase in exposure time and a tendency towards more standardized methods has led industries to develop more powerful light sources and artificial weathering devices. 

Evaluation. For screening stabilities at Interfaces, polymer/mirror samples were exposed in an Atlas Weather-Ometer at 70°C and 50% relative humidity, using continuous radiation... 

Fluorescence spectroscopy and imaging for the evaluation of oxidative stability (weathering) of polymer/pigment compositions under conventional test conditions... 

Favaro, M., Mendichi, R., Ossola, E., Simon, S., et al. (2007). Evaluation of polyma-s for conservation treatments of outdoor exposed stone monuments. Part II Hioto-oxidative and salt-induced weathering of acrylic-silicone mixtures. Polymer Degradation and Stability, 92(3), 335-351. 

Although polymer degradation is more commonly assessed in inert atmosphere, the TGA in air may provide relevant and useful information to the evaluation of the oxidative stability of polymeric materials under natural conditions (weathering, shelf aging, in vivo, etc.). 

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