Purpose of Polymer Analysis

A variety of situations call for the identification of polymers. A customer wishes to paint or glue an item or to use an object in a novel environment. It may be awkward or impossible to obtain the composition from the supplier. In another common case, it may simply be detective work to find a chemical reason why a competitor s product behaves differently from your own. Contaminants in fabrication plants can be very hard to trace. For example, a small amount of a highly unsaturated polymer, such as natural rubber, can prevent the proper cross-linking of a large amount of a more saturated material, such as butyl or ethylene propylene diene monomer (EPDM) rubber. 

Many of the tests described as useful in identification are also run routinely as quality controls on known polymers. Although infrared (IR) spectroscopy is extremely helpful as an identification tool, it is also applied to the measurement of crystallinity and branching in some polymers (notably polyethylene). Physical testing, molecnlar weight determination, and electrical testing have been discussed previously. The larger polymer producers perform almost all of these tests routinely. The smaller, more specialized laboratories of many fabricators and consumers may not possess all of the instruments needed for these tests. Independent laboratories will perform them on a consulting basis. Where the instruments are expensive or the test method is quite involved, recourse to independent laboratories may be wise. 

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