Expansion of the application range of pyrolysis-gas chromatography to copolymer sequence determination: Acrylate copolymers

The sequence distribution, which describes the order of monomers in a copolymer, is notoriously hard to study. The current standard in polymer sequence determination, NMR, is limited to simple copolymers due to lack in resolution and sensitivity. Therefore, an alternative method to determine the sequence of complex copolymers in the form of a developed pyrolysis-GC-MS method was investigated. Pyrolysis-GC-MS was applied to various acrylate copolymers; in the obtained pyrograms clear trimer distributions were observed and identified. Based on these results the sequence of these systems was calculated. The determined sequence values were found to be in line with expectations, demonstrating that the method was suitable for the sequence determination of binary acrylate copolymers. The developed method was also applied on various tertiary acrylate copolymers. Tertiary copolymers form many more distinct trimers rendering assignment more challenging. Nevertheless, based on a combination of chromatographic and mass spectrometric data, all formed trimers were assigned. To the best of our knowledge, this is the first time that a tertiary acrylate is sequenced by pyrolysis-GC.