Imaging chemiluminescence

Norling and A.V Taboesky in Thermal Stability of Polymers, Ed., R.T. Conley, Dekker, New York, NY, USA, 1970, Volume 1, Chapter 5. 

Zaharescu, V. Meltzer and R. Vilcu, Polymer Degradation and Stability, 1999, 64,101. 

Groening and M. Hakkarainen, Journal of Applied Polymer Science, 2002, 

R Wampler and E.J. Levy, Journal of Analytical and Applied Pyrolysis, 1985, 

Pentin, B.N. Tarasevich and B.N. El tsefon, Vestnik-Moskovskii Universitet Khimia, 1973, 14, 13. 

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Imaging chemiluminescence technique. Chemiluminescence analysis is suitable for studying the early stages of the thermal oxidation of rubbers. A weak emission of light formed by chemical reactions appears during the oxidative degradation of hydrocarbons. This technique can be used to depth profile the oxidation of rubbers. MR... 

Abstract The oxidation of polymers such as polypropylene and polyethylene is accompanied by weak chemiluminescence. The development of sensitive photon counting systems has made it comparatively easy to measure faint light emissions and polymer chemiluminescence has become an important method to follow the initial stages in the oxidative degradation of polymers. Alternatively, chemiluminescence is used to determine the amount of hydroperoxides accumulated in a pre-oxidised polymer. Chemiluminescence has also been applied to study how irradiation or mechanical stress affects the rate of polymer oxidation. In recent years, imaging chemiluminescence has been established as a most valuable technique offering both spatial and temporal resolution of oxidation in polymers. This technique has disclosed that oxidation in polyolefins is non-uniformly distributed and proceeds by spreading. 

Keywords Chemiluminescence Imaging chemiluminescence Polyethylene Polypropylene Oxidation PP PE... 

Kohler et al. discussed the potential of the chemiluminescence technique as an industrial test method. Imaging chemiluminescence was used to assess antioxidant performance. An advantage over oven aging was found to be the possibility for evaluation of the oxidative stability of samples with unusual geometries, such as fibres and powder particles [136]. A correlation was also found between oven aging and chemiluminescence measurements on stabilised PP and it was shown that chemiluminescence measurements done at... 

Ahlblad G (1998) Imaging chemiluminescence applied to oxidation of rubber materials and polymers. PhD Thesis, Royal Inst of Technology, Stockholm... 

G. Ahlblad, P. Gijsman, B. Terselius, A. Jansson, and K. Moller, Thermo-oxidative stablility of PP waste films as studied by imaging chemiluminescence, Polym. Degrad. Stab. 2001, 73, 15-22. 

Instrumentation used for polymer oxidative stability (Chapter 11) includes, thermogravimetric analysis, differential scanning calorimetry, evolved gas analysis, infrared spectroscopy and ESR spectroscopy, matrix assisted laser desorption/ionisation mass spectrometry and imaging chemiluminescence is included. 

Ahlblad and co-workers [37] determined the oxidation profiles of polyamide 6,6 using FT-IR spectroscopy and imaging chemiluminescence. FT-IR analysis provides carbonyl index depth profiles and imaging chemiluminescence gives a peroxide depth profile. 

Thermogravimetric analysis Differential thermal analysis Differential scanning calorimetry Thermal volatiUszation analysis Evolved gas analysis Mass spectroscopy methods Matrix-assisted laser desorption/ionization Imaging chemiluminescence... 

Other possible simultaneous techniques in combination with CL are /zFTIR, FTIES and oxygen uptake. Simultaneous FTIES-CL analysis (both emission spectroscopies) has been used to evaluate oxidation models for polypropylene [598]. In a further instrumental advancement, imaging chemiluminescence (ICL) has become available cfr. Chp. 5.6.4.1). Early stages of polymer oxidation can also be studied using 02 exposure and ToF-SIMS analysis [599,600]. 

Polypropylene has been the most studied polymer by means of chemiluminescence. CL has been applied to study the oxidation of PP under diverse conditions, namely after photooxidation [624], in the presence of metal ion prodegradants [625], after storage oxidation [626] as well as under high temperature ageing [627]. The sensitivity of CL has been demonstrated by measurement of complete oxidation curves of single reactor powder particles of PP of 30 (xg mass [608] and by imaging chemiluminescence with a spatial resolution of 20 fxm. CL emission from the isothermal oxidation of PP is fundamentally related to the formation of an oxidation product (excited carbonyl). CL is a very attractive method for studying peroxidation in PP because the measurement is relatively simple and needs little sample preparation, in marked contrast with the conventional iodometric approach. CL has been applied as a technique to measure the hydroperoxide... 

Fig. 5.18. Configuration of an imaging chemiluminescence instrument. After Ahlblad ef a/. [598]. Reprinted itom Polymer Testing 16, G. Ahlblad et al., 59-73, Copyright (1997), with permission of Elsevier.

Table 5.52. Main features of imaging chemiluminescence for polymer studies...

Multi-cell imaging chemiluminescence to map heterogeneous degradation of poiypropyiene plaques. Polymer Degradation and Stahility, 82 (2003), p. 181 -186... 

The chemiluminescence may or may not be uniform throughout the sample (Fig. 10.46) this can be detected by using an imaging chemiluminescence detector. 

Imaging chemiluminescence has also been used to determine oxidation profiles of polyamide 6,6 [26-28]. 

THERMO-OXIDATIVE STABILITY OF PP WASTE FILMS STUDIED BY IMAGING CHEMILUMINESCENCE... 

Hamskog, M., Ahlblad, G., Famert, G., Gijsman, P., and Terselius, B., New multi cell imaging chemiluminescence (ICE) instrument to evaluate the stability of polymers. Polymer Testing, 22 4. 363-369 (2003). 

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