Analysis degradation information

Thermogravimetrical analysis provides information on loss of mass which may be a result of degradation with volatilization of plasticizer component, plasticizer evaporation, or degradation and volatilization of any other component of the tested mixture (most likely polymer and stabilizer because test formulations are usually kept simple). Beeause of these different reasons for mass loss the results are difficult to interpret. In some studies reported here, evaporation loss of plasticizer was distinguished from loss of degradation products by ranning two separate tests one for the pure plasticizer and the other for the entire composition. This may help to better understand reasons for mass loss but it... 

Thermogravimetric analysis provides information that is complementary to that obtained by DSC. The technique is particularly useful where changes of mass occur as a result of drying, volatilization, chemical reaction, and degradation. In thermogravimetric studies, the relevant thermal processes often begin between 100°C and 150°C where adsorbed water or other volatiles are released, followed by... 

Applications of ISS to polymer analysis can provide some extremely useful and unique information that cannot be obtained by other means. This makes it extremely complementary to use ISS with other techniques, such as XPS and static SIMS. Some particularly important applications include the analysis of oxidation or degradation of polymers, adhesive failures, delaminations, silicone contamination, discolorations, and contamination by both organic or inorganic materials within the very outer layers of a sample. XPS and static SIMS are extremely comple-mentar when used in these studies, although these contaminants often are undetected by XPS and too complex because of interferences in SIMS. The concentration, and especially the thickness, of these thin surfiice layers has been found to have profound affects on adhesion. Besides problems in adhesion, ISS has proven very useful in studies related to printing operations, which are extremely sensitive to surface chemistry in the very outer layers. 

Capillary HPLC-MS has been reported as a confirmatory tool for the analysis of synthetic dyes [585], but has not been considered as a general means for structural information (degradant identification, structural elucidation or unequivocal confirmation) positive identification of minor components (trace component MW, degradation products and by-products, structural information, thermolabile components) or identification of degradation components (MW even at 0.01 % level, simultaneous mass and retention time data, more specific and much higher resolution than PDA). Successful application of LC-MS for additive verification purposes relies heavily and depends greatly on the quality of a MS library. Meanwhile, MB, DLI, CF-FAB, and TSP interfaces belong to history [440]. 

HPLC-NMR analysis in a closed-circuit reveals the stereochemical information for elucidating the structures of unknown compounds (Albert 2002). In contrast to the technique of off-line separation, sample collection, and peak identification closed-circuit analysis guarantees the absence of isomerization and degradation. Very often only small amounts of sample are available after extraction. 

As is evident in the many examples selected in this chapter to illustrate the molecular characterisation and analysis of polymer degradation and oxidation processes, almost, without exception, each study or investigation cited has involved use of more than one analytical method or characterisation technique, often many more than two. This clearly emphasises the importance of using a multi-technique approach to provide supportive, complementary and confirmatory information, since each technique or method yields a different aspect of the degradation/oxidation process in polymers. 

This book is divided up into sections. The first three chapters provide a background sections that follow contain chapters dealing with polymer chain analysis, polymer morphology and structure, polymer degradation, polymer product analysis and support techniques. These are listed in more detail in Chapter 1, which also expands more fully on our industrial perception of the requirements for competence and appreciation in all techniques and methods for polymer molecular characterization and analysis. We hope you find this book of value and its approach both unique and technically informative and useful. 

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