TABLE OF CONTENTS Polymers being with few exceptions, solid substances, cannot be directly analysed using gas chromatography. However, it is possible by the application of well-controlled chemical reactions to decompose polymers to simpler volatile substances that are amenable to gas chromatography and thereby one can obtain information concerning the original polymer.
A further special case of reaction gas chromatography involves pyrolysis (or photolysis) of the polymer in the absence of oxygen (Section 3.7) and examination of the volatiles produced by gas chromatography to provide information on the structure of the original polymer.
Further complementary techniques can be applied to obtain even more information. Thus PGC can be coupled with mass spectrometry or NMR spectroscopy.
Information on the availability of gas chromatographs is supplied in Appendix 1.
Ester groups occur in a wide range of polymers, e.g., PET. The classic chemical method for the determination of ester groups, namely saponification, can be applied to some types of polymer. For example, copolymers of vinyl esters and esters of vinyl esters and esters of acrylic acid can be saponified in a sealed tube with 2 M sodium hydroxide. The free acids from the vinyl esters can then be determined by gas chromatography. The alcohols formed by the hydrolysis of the acrylate esters are determined by gas chromatography. Polymethyl acrylate can be hydrolysed rapidly and completely under alkaline conditions; however, the monomer units in PMMA prepared and treated similarly are resistant to hydrolysis although their benzoate...
