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Desorption electrospray ionisation mass spectrometry of stabilised polyesters reveals activation of hindered amine light stabilisers

Journal Article


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Abstract


  • The use of hindered amine light stabilizers (HALS) to retard thermo- and photo-degradation of polymers has become increasingly common. Proposed mechanisms of polymer stabilisation involve significant changes to the HALS chemical structure; however, reports of the characterisation of these modified chemical species are limited. To better understand the fate of HALS and determine their in situ modifications, desorption electrospray ionisation mass spectrometry (DESI-MS) was employed to characterise ten commercially available HALS present in polyester-based coil coatings. TINUVIN® 770, 292, 144, 123, 152, and NOR371; HOSTAVIN® 3052, 3055, 3050, and 3058 were separately formulated with a pigmented, thermosetting polyester resin, cured on metal at 262 °C and analysed directly by DESI-MS. High-level ab initio molecular orbital theory calculations were also undertaken to aid the mechanistic interpretation of the results. For HALS containing N-substituted piperidines (i.e., N–CH3, N–C(O)CH3, and N–OR) a secondary piperidine (N–H) analogue was detected in all cases. The formation of these intermediates can be explained either through hydrogen abstraction based mechanisms or direct N–OR homolysis with the former dominant under normal service temperatures (ca. 25–80 °C), and the latter potentially becoming competitive under the high temperatures associated with curing (ca. 230–260 °C).

Authors


  •   Paine, Martin (external author)
  •   Gryn'ova, Ganna (external author)
  •   Coote, M L. (external author)
  •   Barker, Phil J.
  •   Blanksby, Stephen J. (external author)

Publication Date


  • 2014

Citation


  • Paine, M. R.L., Gryn'ova, G., Coote, M. L., Barker, P. J. & Blanksby, S. J. (2014). Desorption electrospray ionisation mass spectrometry of stabilised polyesters reveals activation of hindered amine light stabilisers. Polymer Degradation and Stability, 99 223-232.

Scopus Eid


  • 2-s2.0-84892368794

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=2435&context=smhpapers

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/1417

Number Of Pages


  • 9

Start Page


  • 223

End Page


  • 232

Volume


  • 99

Abstract


  • The use of hindered amine light stabilizers (HALS) to retard thermo- and photo-degradation of polymers has become increasingly common. Proposed mechanisms of polymer stabilisation involve significant changes to the HALS chemical structure; however, reports of the characterisation of these modified chemical species are limited. To better understand the fate of HALS and determine their in situ modifications, desorption electrospray ionisation mass spectrometry (DESI-MS) was employed to characterise ten commercially available HALS present in polyester-based coil coatings. TINUVIN® 770, 292, 144, 123, 152, and NOR371; HOSTAVIN® 3052, 3055, 3050, and 3058 were separately formulated with a pigmented, thermosetting polyester resin, cured on metal at 262 °C and analysed directly by DESI-MS. High-level ab initio molecular orbital theory calculations were also undertaken to aid the mechanistic interpretation of the results. For HALS containing N-substituted piperidines (i.e., N–CH3, N–C(O)CH3, and N–OR) a secondary piperidine (N–H) analogue was detected in all cases. The formation of these intermediates can be explained either through hydrogen abstraction based mechanisms or direct N–OR homolysis with the former dominant under normal service temperatures (ca. 25–80 °C), and the latter potentially becoming competitive under the high temperatures associated with curing (ca. 230–260 °C).

Authors


  •   Paine, Martin (external author)
  •   Gryn'ova, Ganna (external author)
  •   Coote, M L. (external author)
  •   Barker, Phil J.
  •   Blanksby, Stephen J. (external author)

Publication Date


  • 2014

Citation


  • Paine, M. R.L., Gryn'ova, G., Coote, M. L., Barker, P. J. & Blanksby, S. J. (2014). Desorption electrospray ionisation mass spectrometry of stabilised polyesters reveals activation of hindered amine light stabilisers. Polymer Degradation and Stability, 99 223-232.

Scopus Eid


  • 2-s2.0-84892368794

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=2435&context=smhpapers

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/1417

Number Of Pages


  • 9

Start Page


  • 223

End Page


  • 232

Volume


  • 99