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V. Archodoulaki, S. Lüftl, S. Seidler:
"Degradation Behavior of Polyoxymethylene: Influence of Different Stabilizer Packages";
Journal of Applied Polymer Science, Vol. 105 (2007), 6; 3679 - 3688.

Stabilizer effects of two types (homopolymer and copolymer) of commercially available polyoxymethylenes containing two different stabilizer packages under various aging conditions have been studied by the application of thermogravimetric analysis coupled with
mass spectrometry. Increasing yellowness during thermooxidative
aging has been observed. Investigations of the melt volume rate have proved that the UV-stabilized materials exhibit a higher increase in the melt volume rate after oven aging, which is caused by reactions of the additives, than the solely heat-stabilized materials. The thermogravimetric analysis/mass spectrometry investigations have
proved broad synergy effects between the heat- and UVstabilizer
systems. The formation of chains with thermally stable end groups or of cyclic products proceeds during
aging, particularly in the presence of UV stabilizers. This
formation might be the result of intermolecular transacetalization
reactions. The degradation behavior of UV-irradiated
homopolymer and copolymer samples has also been
investigated. Oven storage and weathering cause comparable
shifts in the derivative thermogravimetry traces, so
similar damage reactions can be suggested.

ageing; degradation; irradiation; stabilization; thermogravimetric analysis (TGA)

http://dx.doi.org/10.1002/app.26524