Liquid Chromatography Of Synthetic Polymers

This book elucidates the peculiar phenomenon of entropy/enthalpy compensation that takes place in high performance liquid chromatography (HPLC) of polymers. Numerous publications, including some books, are devoted to molecular characterization of synthetic polymers, materials presently produced in large and steadily growing quantities, applying methods of HPLC. A knowledge of the molecular characteristics of polymers is indispensable, not only for their proper applications but also for their recycling and remediation. Polymer scientists generally focus on synthesis and potential applications of polymers while not giving due attention to an important central link, their comprehensive characterization in context of development of structure-property correlations. To fill this gap is one of the aims of the present book. The process of entropy/enthalpy compensation plays a decisive role in the advanced method of polymer characterization such as liquid chromatography at critical conditions, eluent gradient interaction chromatography, and temperature gradient interaction chromatography. All chemists working on any aspect of polymer science will find this book a valuable resource for the development of structure-property correlations.

The report comprises a state-of-the-art overview of the subject of molecular c099 characterisation, supported by an extensive, indexed bibliography. The current methodology for GPC is described along with its use in combination with other techniques such as light scattering and viscosity c094. An additional indexed section containing several hundred abstracts from the Rapra Polymer Library database provides useful references for further reading.

MALDI-TOF mass spectrometry is one of the latest and most fascinating new developments in the analysis of organic compounds. Originally developed for the analysis of biomolecules, it has developed into one of the most powerful techniques for the characterization of synthetic polymers. This book describes the fundamentals of the MALDI process and the technical features of MALDI-TOF instrumentation. It reviews the application of MALDI-TOF for identification, chemical and molar mass analysis of synthetic polymers. With many examples, the monograph examines experimental protocols for the determination of endgroups, the analysis of copolymers and additives, and the coupling of liquid chromatography and MALDI-TOF in detail.

In the last decade, the use of interaction chromatography and hyphenated techniques has become increasingly important for the characterization of polymeric materials. Interaction chromatography allows separation by other structural features than molar mass, while hyphenation with mass spectroscopy or spectroscopic techniques provides detailed characterization of the separated chromatographic fractions. This chapter gives an overview of the principles and applications of interaction chromatography and the information that can be determined by hyphenation of polymer chromatography with mass spectrometry and spectroscopic techniques.

The main subject of this book is the characterization of plastics. To a high degree the properties of these polymers depend on the distribution of the molar mass and of other structural features, and small deviations frequently have a great effect. Therefore the characterization of polymers cannot be restricted to the determination of mean values but must yield information on these distributions. Using classical methods, the analytical fractionation of polymer homologues and structurally isomeric polymers is extremely time-consuming. Therefore, efficient chromatographic techniques are being increasingly employed in modern polymer characterization. In the first place, high-performance liquid chromatography is applied, in the form of size exclusion chromatography. It is also possible, however, to use other separation modes. More space is devoted to these other possibilities in this volume than is merited by their current range of applications, as the author believes that many separation problems will be solved by separation techniques of the non-exclusion type. Nevertheless, much emphasis is placed on size exclusion chromatography. Not only because of its current wide range of applications, but also because its relative importance, as a complement to other chromatographic techniques may even increase in the forthcoming years. This book is the first to cover all phenomena related to the above considerations. Starting with an introduction to basic liquid chromatography and to polymer science, it deals with the adsorption behaviour of polymers, with gradient techniques, with the kinetic band broadening in liquid chromatography, with instrumental features and packing materials. The book consists of four balanced sections and related information from about 1800 references is compiled in the tables. Some 250 figures and 30 tables will help give the reader a clear insight of the topics discussed. The book is aimed at helping the analyst or polymer chemist who is looking for information about chromatographic methods for the characterization of polymers.

"The problems involved in separating complex macromolecules require under standing not only the chromatographic process but also the physicochemical behavior of the solutes." This sentence from the pen of Phyllis R. Brown 1, University of Rhode Island, can certainly be applied to synthetic copolymers whose structure is very complex indeed. Thus it may be forgiven that a book on copolymer HPLC has been written not by a trained chromatographer but by someone from the polymer side. The HPLC of synthetic polymers is often understood to mean only a synonym for size exclusion chromatography. The latter method separates polymers according to the size of the macromolecules and enables the molecular weight distribution of a sample to be evaluated. But as early as 1936, Mark and Saito attempted chromatographic fractionation of cellulose acetate on a charcoal-like adsorbent made from blood. HPLC adsorption chromatography was first applied to copolymer analysis by Teramachi et al. in 1979. Since then, another branch of polymer HPLC has arisen which has the capacity of separating copolymers by composition and enables the chemical composition distribution to be evaluated. The technique requires a suitable elution program and is mainly carried out as gradient elution.

This book is a contemporary review of selected subjects in liquid chromatography, especially of the technical development, rather than the applications. The subjects are focused in the biomedical and environmental fields. This is also a troubleshooting record. Complex analytical problems such as sensitivity (sensitive detection by chemiluminescence, coulometric detection, laser based detection, necessity of degassing the system for sensitive detection), difficulty (free radical detection by Electron Spin Resonance, Polarimeter for chiral recognition) and reproducibility (packings for chiral separation and stable bonded silica gels) are solved. Theoretically and environmentally important miniaturizations are described. Individual chapters written by specialists provide information beyond what can be found in general textbooks of liquid chromatography.

Size-exclusion chromatography (SEC) is used for the characterization and/or separation of macromolecules. Size-based sampling of column pore volume provides information in terms of the molar mass averages and distributions of disperse polymers. The history of the development, the basic theory of column separations, calibration, and detection strategies for obtaining absolute molar mass information are described, as are modern multidetector techniques and the incorporation of SEC into two-dimensional liquid chromatographic arrangements.