Two-dimensional correlation analysis study of the curing process of phenylethynyl end-capped imide model compounds

The phenylethynyl end-capped imide model compounds 6F-PDA-PEAP and 6F-ODA-PEAP were prepared for detailed investigation of the thermal cure process. To probe the spectral changes of ethynyl CC moieties as well as imide rings and phenyl rings in PDA and ODA units during the thermal curing, we applied two-dimensional (2D) correlation analysis to the infrared spectra of 6F-PDA-PEAP and 6F-ODA-PEAP films. Thermal curing of 6F-PDA-PEAP and 6F-ODA-PEAP was influenced by molecular structure, and it induced spectral changes of CC moieties as well as imide rings and phenyl rings in PDA and ODA units. The thermal curing of 6F-PDA-PEAP and 6F-ODA-PEAP films induces the intensity changes of bands of imide and phenyl rings in PDA and ODA units before that of CC moieties.