Effect of Aggregation Structure on Thermal Expansion Behavior of Polyimide Films with Different Thickness

Low-power laser manufacturing of copper tracks on 3D printed geometry using liquid polyimide coating

“…33 However, these peaks are very close to the alkoxy/phenyl C–O stretch at 1105 cm −1 and the CO bending vibrations at 720 cm −1 , hence these peaks are difficult to be unambiguously identified. 30,34…”

“…Other imide peaks include the 1110 cm -1 C-N-C transverse stretching and C-N-C out-of-plane bending between 720-740 cm -1 33 . However, these peaks are very close to the alkoxy/phenyl C-O stretch at 1105 cm -1 and the C=O bending vibrations at 720 cm -1 , hence these peaks are difficult to be unambiguously identified 34,30 . The prominent peak at 1670 cm -1 is unusually broad and encompasses smaller adjacent peaks, which indicates the presence of C=O groups from secondary amides as well as acid groups.…”

“…In this work, PAA-based PI liquid was spin-coated on a 3D-printed polyetherimide (PEI) substrate and heated in an oven between 120 and 200 °C for 20 minutes. Imide formation is distinguished by the appearance of the following peaks on an FTIR spectrum: C=O stretching at 1780 and 1720 cm -1 (asymmetric and symmetric stretching, respectively) and C-N-C axial stretching at ~ 1380 cm -1[32][33][34] . Amides, on the other hand, are recognised by a peak between 1650-1690 cm -1 corresponding to C=O stretching and a peak at 1550 cm -1 from the C-N-H vibrations30,32,34 .…”

“…Imide formation is distinguished by the appearance of the following peaks on an FTIR spectrum: C=O stretching at 1780 and 1720 cm -1 (asymmetric and symmetric stretching, respectively) and C-N-C axial stretching at ~ 1380 cm -1[32][33][34] . Amides, on the other hand, are recognised by a peak between 1650-1690 cm -1 corresponding to C=O stretching and a peak at 1550 cm -1 from the C-N-H vibrations30,32,34 . C=O vibrations from carboxylic acids also appear at around 1680-1700 cm -1 .…”

“…Other imide peaks include the 1110 cm -1 C-N-C transverse stretching and C-N-C out-of-plane bending between 720-740 cm -1 33 . However, these peaks are very close to the alkoxy/phenyl C-O stretch at 1105 cm -1 and the C=O bending vibrations at 720 cm -1 , hence these peaks are difficult to be unambiguously identified34,30 .…”