Network Degradation Assessed by Evolved Gas Analysis-Mass Spectrometry Combined with Principal Component Analysis (EGA-MS-PCA): A Case of Thermo-Oxidized Epoxy/Amine Network

To study the degradation of thermosetting polymers, we apply a novel method to simultaneously study the chemical structural changes and network topology: evolved gas analysis-mass spectrometry combined with principal component analysis (EGA-MS-PCA). This technique was applied to thermo-oxidative aging of an epoxy/amine network. The signals of various pyrolyzates remain overlapped in the complicated EGA-MS profiles. The key fragments of thermally evolved gases derived from the components of the network are effectively selected by PCA from the complicated EGA-MS profiles. EGA-MS-PCA provides information on the network structure: (i) the oxidized fraction of cross-links (i.e., chemically damaged cross-links), (ii) the relative quantification of unbonded chains, and (iii) the formation of dangling chains. The proposed technique can simultaneously characterize chemical degradation and network structural properties. This characterization technique can be utilized as a generally applicable tool for determining the structural durability of thermosetting polymers.

Automated summary

To study the degradation of thermosetting polymers, a novel method called evolved gas analysis-mass spectrometry combined with principal component analysis (EGA-MS-PCA) was applied. This technique provides information on the chemical structural changes and network topology of the polymers. By effectively selecting key fragments from the complicated EGA-MS profiles, the technique can simultaneously characterize chemical degradation and network structural properties. It can be used as a generally applicable tool for determining the structural durability of thermosetting polymers.