Analysis additives

4 Infrared spectroscopy (Fourier transform infrared (FTIR) 

5 High performance liquid chromatography and with mass 

7 Scanning electron microscopy with elemental X-ray analysis 571 

8 Cross-linking agents and cure accelerators (rubber) 585 

Comprehensive Analytical Chemistry, Volume 53 ISSN 0166-526X, DOI 10.1016/S0166-526X(08)00414-5 

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The causes of low pressure, for example, could be cither hydraulic or mechanical. In many cases of failure analysis, asking Wliy. and Wliat and answering those questions, until you can no longer ask why , will almost always get you to the answer. If all evidence leads to a mechanical reason for the failure, the problem is probably maintenance induced. If the evidence leads to a hydraulic reason for the failure, the problem is eitJier operations or design induced. In cases where the reason for failure was not determined, a more extensive analysis is necessary. The additional analysis is recommended to take advantage of the pump supplier experience in identifying the root cause. 

The analysis of performance provides a powerful technique for identifying potential for improvement. As discussed in the previous chapter, trends can be spotted and action taken to identify and correct any unwanted development. Additionally, analysis of data can help with the identification of underlying problems. For example, a higher than average number of eye injuries at a particular facility might justify further investigation. 

H. J. Goites, G. E. Bormett and J. D. Graham, Quantitative polymer additive analysis by multidimensional cliromatography using online coupled microcolumn size exclusion cliromatography as a preliminary separation , 7. Microcolumn Sep. 4 51 - 57 (1992). 

Supplemental files (review aids) are any data set needed by the reviewer for additional analysis purposes that cannot be readily extracted from the PDF report or additional information in electronic format that would enhance the reviewer s understanding or facilitate presentation of the data. 

This book summarises the enormous work done and published by many scientists who believe in polymer analysis. It is humbling to notice how much collective expertise is behind the current state-of-the-art in poly-mer/additive analysis and how little is at the command of any individual. The high degree of creativity and ingenuity within the international scientific community is inspiring. The size of the book shows the high overall productivity. Even so, only a fraction of the pertinent literature was cited. 

Selection of additives is critical and often a proprietary knowledge. Computer-aided design is used for organic compounds as active additives for polymeric compositions [1]. An advantage of virtual additives is that they do not require any additive analysis ... 

Table 1.10 Basic needs in polymer/additive analysis...

The ability to reproducibly determine the additive package present in polymers is of major concern to resin manufacturers, converters (compounders), end-users, regulators and others. Qualitative and/or quantitative knowledge of compounding ingredients, to be obtained by additive analysis, may be needed in various stages of a product lifecycle (Table 1.11). 

It is equally important for the manufacturer and regulator to know the level of additives in a polymer material to ensure that the product is fit for its intended purpose. Additive analysis marks sources of supply, provides a (total) process signature and may actually be used as a fingerprint of a polymeric material, in particular as molecular characterisation of the polymer... 

Apart from routine quality control actions, additive analysis is often called upon in relation to testing additive effectiveness as well as in connection with food packaging and medical plastics, where the identities and levels of potentially toxic substances must be accurately known and controlled. Food contact plastics are regulated by maximum concentrations allowable in the plastic, which applies to residual monomers and processing aids as well as additives [64-66]. Analytical measurements provide not only a method of quality control but also a means of establishing the loss of stabilisers as a function of material processing and product ageing. 

Figure 1.2 Number of scientific publications per year on polymer/additive analysis. Source Chem. Abstr.

Table 1.13, which lists the main techniques used for polymer/additive analysis, allows some interesting observations. Classical extraction methods still score very high amongst sample preparation techniques on the other hand, not unexpectedly, inorganic analysis methods are not in frequent use for separation purposes... 

In compliance with EURACHEM/CITAC Guide 2 [72] polymer/additive analysis can be considered as a collection of discrete subtasks (Figure 1.3), each consisting of a number of unit processes, themselves composed of modules containing routine unit operations. The unit processes are characterised as being separated by natural dividing lines at which work can be interrupted and the test portion can be stored without detriment before the next step. 

Critical expert forums for all aspects related to the analytics of additives in polymers are the ACS Analytical Division, SPE Polymer Analysis and Polymer Modifiers Additives Analysis Divisions or the German Arbeitskreis Polymeranalytik (cf. homepage DKI). 

Figure 1.3 Breakdown of a polymer/additive analysis project into unit operations...

More recently, the same author [41] has described polymer analysis (polymer microstructure, copolymer composition, molecular weight distribution, functional groups, fractionation) together with polymer/additive analysis (separation of polymer and additives, identification of additives, volatiles and catalyst residues) the monograph provides a single source of information on polymer/additive analysis techniques up to 1980. Crompton described practical analytical methods for the determination of classes of additives (by functionality antioxidants, stabilisers, antiozonants, plasticisers, pigments, flame retardants, accelerators, etc.). Mitchell... 

Progress in the field of polymer/additive analysis in the last three decades can best be illustrated by an old recipe for the direct determination of organotin stabilisers in PVC [142] ... 

It should be understood that the reported practices of polymer/additive analysis, being the focus of this book, equally well apply to additive analysis of rubbers, textile fibres, surface coatings, paints, resins, adhesives, paper and food, but specific product knowledge gives the edge. Both fresh and aged materials may be analysed, as well as those of both industrial and forensic origin. 

Figure 1.5 Road map of polymer/additive analysis. Reprinted with permission from LC.GC Europe, Vol. 14, Number 8, August 2001. LC.GC Europe is a copyrighted publication of Advanstar Communications Inc. All rights reserved...

The final chapter summarises the book with special emphasis on the future of polymer/additive analysis. The methods, results and their evaluation presented in this chapter encompass all material developed in the book s previous chapters. Three appendices contain lists of symbols, describe the functionality of common additives (as a reminder) and show an excerpt of an industrial polymer additive database. 

D.O. Hummel, Atlas of Plastics Additives Analysis by Spectro-metric Methods, Springer-Verlag, Berlin (2002). 

Polymer identification 30 2.5 Class-specific polymer/additive analysis. 47... 

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