Hindered amine light stabilizers

Partial structure of a typical hindered amine light stabilizer
Example structure of a commercial HAL

Hindered amine light stabilizers (HALS) are chemical compounds containing an amine functional group that are used as stabilizers in plastics and polymers.[1] These compounds are typically derivatives of tetramethylpiperidine and are primarily used to protect the polymers from the effects of photo-oxidation; as opposed to other forms of polymer degradation such as ozonolysis.[2][3] They are also increasingly being used as thermal stabilizers,[4] particularly for low and moderate level of heat, however during the high temperature processing of polymers (e.g. injection moulding) they remain less effective than traditional phenolic antioxidants.[5]

  1. ^ Zweifel, Hans; Maier, Ralph D.; Schiller, Michael (2009). Plastics additives handbook (6th ed.). Munich: Hanser. ISBN 978-3-446-40801-2.
  2. ^ Pieter Gijsman (2010). "Photostabilisation of Polymer Materials". In Norman S. Allen (ed.). Photochemistry and Photophysics of Polymer Materials Photochemistry. Hoboken: John Wiley & Sons. pp. 627–679. doi:10.1002/9780470594179.ch17. ISBN 978-0-470-59417-9..
  3. ^ Klaus Köhler; Peter Simmendinger; Wolfgang Roelle; Wilfried Scholz; Andreas Valet; Mario Slongo (2010). "Paints and Coatings, 4. Pigments, Extenders, and Additives". Ullmann's Encyclopedia Of Industrial Chemistry. doi:10.1002/14356007.o18_o03. ISBN 978-3-527-30673-2.
  4. ^ Gijsman, Pieter (November 2017). "A review on the mechanism of action and applicability of Hindered Amine Stabilizers". Polymer Degradation and Stability. 145: 2–10. doi:10.1016/j.polymdegradstab.2017.05.012.
  5. ^ Gensler, R; Plummer, C.J.G; Kausch, H.-H; Kramer, E; Pauquet, J.-R; Zweifel, H (February 2000). "Thermo-oxidative degradation of isotactic polypropylene at high temperatures: phenolic antioxidants versus HAS". Polymer Degradation and Stability. 67 (2): 195–208. doi:10.1016/S0141-3910(99)00113-5.