Deformulation of polymers

Forrest, Analysis of Plastics, Rapra Review Report No. 

Crompton, Manual of Plastics Analysis, Plenum Press, New York, NY (1998). 

Scheirs, Compositional and Failure Analysis of Polymers, A Practical Approach, John Wiley Sons, Ltd, Chichester (2000). 

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Table 3.4 compares the performance of dissolution and various extraction procedures. Chapter 9 addresses in more detail direct methods of deformulation of polymer/additive dissolutions, i.e. without separation... 

Direct Methods of Deformulation of Polymer/Additive Dissolutions... 

Many polymer companies have not maintained a cadre of experts on the analysis of additives in polymers. Consequently, there is a need to train a new generation of people about additives and methods of deformulating them. Outsourcing of polymer/additive... 

Whereas SEC is the dominant technique for the characterisation of polymers, various nonexclusion liquid chromatographic (NELC) methods, such as GPEC and LACCC offer equally valid possibilities for deformulation of complex polymer systems. In fact, molecular characterisation of polymers in the precip-itation/adsorption mode (gradient HPLC) enables differences in chemical structure and composition to be... 

The mass spectrometer is a mass-flow sensitive device, which means that the signal is proportional to the mass flow dm/dl of the analyte, i.e. the concentration times the flow-rate. It is only now possible to realise the high (theoretically unlimited) mass range and the high-sensitivity multichannel recording capabilities that were anticipated many years ago. Of considerable interest to the problem of polymer/additive deformulation are some of the latest developments in mass spectrometry, namely atmospheric pressure ionisation (API), and the revival of time-of-flight spectrometers (allowing GC-ToFMS, MALDI-ToFMS, etc.). 

Applications Applications of SEC-FTIR include quantitative analysis of copolymers [701] product deformulation of hot melt adhesives characterisation of polymer compositional heterogeneity analysis of complex mixtures of urethane oligomers and eventually also the identification and quantitative analysis of polymer additives... 

Applications A limited number of papers refer to the use of AAS in relation to polymer/additive deformulation. Elemental analysis of polymers and rubbers by AAS may be carried out after dissolution in an organic solvent (Table 8.21), after oxidative wet digestion (Table 8.12), after dry ashing (Table 8.22) or directly in the solid state (Table 8.23). 

In polymer/additive deformulation (of extracts, solutions and in-polymer), spectroscopic methods (nowadays mainly UV, IR and to a lesser extent NMR followed at a large distance by Raman) play an important role, and even more so in process analysis, where the time-consuming chromatographic techniques are less favoured. Some methods, as NMR and Raman spectrometry, were once relatively insensitive, but seem poised to become better performing. Quantitative polymer/additive analysis may benefit from more extensive use of 600-800 MHz 1-NMR equipped with a high-temperature accessory (soluble additives only). 

Despite the fact that polymer/additive analysis is a growth area (Figure 1.2), and taking into account the aforementioned considerations, it could well be that the near future will see a more modest increase beyond the current 400 research papers per year on the topic of polymer/additive deformulation. This book has provided a roadmap to polymer/additive analysis. It is up to the users to make ingenious use of the (necessarily limited) equipment at their disposal for their specific problemsolving cases. 

Kilz, R, Kruger, R., Much, H., Schulz, G. (1995). Two-Dimensional chromatography for the deformulation of complex copolymers, in Chromatographic Characterization of Polymers Hyphenated and Multidimensional Techniques. T. Provder, H.G. Barth, M.W. Urban, Editors, American Chemical Society, Washington. DC. 

The versatility of the 2D approach is illustrated with a four-arm starshaped block copolymer (a mixture of 16 components), which was synthesized in our laboratories to understand and demonstrate the advantages of 2D chromatography. These 16 components are a mixture of four different styrene-butadiene (St-Bd) copolymer compositions, each consisting of four molar masses (the St-Bd precursor with one to four arms). Another polymer investigated is a real-world application the deformulation of a telomeric aliphatic polyester. 

The high resolution of LC-SEC separations and the full automation using 2D-CHROM software enable the reliable and comprehensive characterization and deformulation of complex analytes like copolymers, polymer blends, and additives. 2D chromatography will become a powerful tool with flexible and easy-to-use software. Basically, all types of LC methods can be combined to give superior resolution and reproducibility. 

Pyrolysis of these macromolecules produces characteristic pyrogram (pyrolysis chromatogram) profiles that are indicative of the polymers. Individual fragments help in the deconstruction or deformulation of the polymer. Many polar macromolecular systems produce high yields of monomer by pyrolysis, which aids in the qualitation and the quantitation of polymers as well as copolymer systems. This type of information can be valuable not only in terms of characterizing the polymer, but also in... 

KUz P, Kruger RP, Much H, Schulz G (1995) Two-Dimensional Chromatography for the Deformulation of Complex Copolymers. In Provder T., Barth H.G., Urban M.W. (Eds.) Chromatographic Characterization of Polymers, Hyphenated and Multidimensional Techniques. ACS, Washington, DC, p 223... 

The PDA can monitor the separation at hundreds of wavelengths simultaneously in the range from 190 to 800 nm. This makes it possible to generate the actual UV spectra of polymers and additives and evaluate the chemical composition distribution. Block SBR copolymers are distinguishable from random copolymers [8]. Spectral libraries can be created for known polymers and additives to assist identification and deformulation of unknowns. 

Asher el al. [423] have indicated that UVRRS may be used as a technique for speciation of aromatic ring systems in complex matrices of industrial interest. This result might suggest an extension to direct deformulation of a complex mixture of additives in polymers provided that excitation can selectively occur within a discrete absorption band of each analyte. However, at the same time this requirement may easily turn out to be the major limitation in practical applicability as virtually identical UV spectra (or kmax) are often observed for a variety of stabilisers cfr. Chp. 1.1). Klenerman et al. [424]... 

PyGC-MS permits direct deformulation of solid polymer/additive matrices, independently of cross-linking, filler or pigmentation type. The technique allows the determination of the composition of polymer and additives. Liebmann et al. [783] used... 

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