Evaluation of poly(ethylene terephthalate) photostabilisation using FTIR spectrometry of evolved carbon dioxide
Tipo
Artigo
Data de publicação
2009
Periódico
Polymer Degradation and Stability
Citações (Scopus)
22
Autores
Fechine G.J.M.
Christensen P.A.
Egerton T.A.
White J.R.
Christensen P.A.
Egerton T.A.
White J.R.
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Resumo
Carbon dioxide evolution from poly(ethylene terephthalate) (PET) films during ultraviolet (UV) exposure has been monitored using FTIR interrogation of the atmosphere surrounding the test pieces. Measurement periods as little as 4 h could easily discriminate between CO2 emission rates when tests were conducted to investigate the effect of using different reaction atmospheres or of including UV absorber in the PET samples. Samples containing UV absorbers either homogeneously distributed through the film or in thin surface layers (∼0.7 μm thick) were also tested. Relatively small reductions in CO2 emission rates were observed with samples containing UV absorbers but the rates were not very sensitive to the distribution and concentration of the absorbers. A thin surface layer containing only 2% stabiliser (equivalent to 0.23% stabiliser when averaged over the whole film thickness) provided oxidation reduction similar to that observed when 1% stabiliser was distributed evenly throughout the sample. Tests were conducted in wet oxygen, dry oxygen and dry nitrogen. For as-received bi-axially drawn PET film containing no absorber, the CO2 emission rate under UV illumination in wet oxygen was much higher than in dry oxygen or dry nitrogen. For as-received PET the difference between the rates observed in dry oxygen and dry nitrogen was small. For PET films that had been pre-exposed to UV (for 9 days) prior to insertion into the in situ CO2 measurement cell the rate of CO2 generation in oxygen was significantly larger than that in nitrogen. In both nitrogen and oxygen the presence of UV absorbers significantly decreased the rate of CO2 generation. © 2008 Elsevier Ltd. All rights reserved.
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Assuntos Scopus
Carbon dioxide evolutions , CO2 emission , Dry nitrogens , Dry oxygens , Emission rates , FTIR spectrometries , Homogeneously distributed , In-situ , Measurement cells , PET films , Poly(ethylene terephthalate) , Reaction atmospheres , Small reductions , Stabiliser , Thin surface layers , Ultra violets , UV absorbers , UV degradation , UV illuminations , Wet oxygens