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Handbook of Size Exclusion Chromatography and Related ...

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Preface to the First<br />

Edition<br />

Molecular weight <strong>and</strong> molecular weight distribution are well known to affect the<br />

properties <strong>of</strong> polymeric materials. Even though for decades viscosity has been an<br />

integral part <strong>of</strong> product specifications used to characterize molecular weight <strong>of</strong><br />

polymeric materials in industry, the need to define the molecular weight<br />

distribution <strong>of</strong> a product has attracted little attention. However, in recent years<br />

producers <strong>and</strong> users <strong>of</strong> polymeric materials have become ever more interested in<br />

value-added polymers with not only specific molecular weights but also optimal<br />

molecular weight distribution to <strong>of</strong>fer performance advantages to products.<br />

In fact, molecular weight distribution has become an important marketing<br />

feature for polymeric products in the 1990s. It is very common these days to see<br />

new grades <strong>of</strong> polymeric materials introduced to the marketplace that are specially<br />

designed to have either narrow or bimodal molecular weight in composition<br />

distribution throughout the entire molecular weight distribution. Therefore, the<br />

need to improve the analytical capability in R&D to characterize molecular weight<br />

distribution by size exclusion chromatography or gel permeation chromatography<br />

has become increasingly urgent in recent years.<br />

Determination <strong>of</strong> molecular weight distribution <strong>of</strong> a polymer is very <strong>of</strong>ten<br />

not a simple task. This is one <strong>of</strong> the reasons it is still not commonly used as a final<br />

product specification. Many books have been published on size exclusion<br />

chromatography. However, there has still been a need for a book that stresses<br />

practical applications <strong>of</strong> size exclusion chromatography to the important<br />

© 2004 by Marcel Dekker, Inc.

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