Gas chromatography (GC) is an established analytical technique which is useful for the characterization of coatings and related materials. With the introduction of chemically inert and thermally stable fused silica capillary columns, many volatile and semivolatile polar compounds can now be chromatographed easily. Nonvolatile polymers used in coatings can be routinely characterized by pyrolysis-gas chromatography-mass spectrometry (pyrolysis-GC-MS).
Practical examples are presented showing how GC and pyrolysis-GC-MS can be used to monitor the quality of raw materials, resolve manufacturing problems and field complaints, and aid in the reverse engineering of various products. Routine quantitative GC methods, such as the analysis of coalescent agents in latex paint and residual monomers in latex emulsions, are illustrated. Examples are given showing how GC is used for the analysis of raw materials like mineral spirits and fatty acids. GC is also used to characterize and quantitate additives like low molecular weight nonionic surfactants, waxes and oils, and mildewcides. Headspace sampling is used for identifying odor problems and analyzing samples for which solvent dilution is not appropriate. The usefulness of pyrolysis-GC-MS in the characterization of several different types of polymers is demonstrated.