Modification of Macromolecules of Polyimide Films by Electron Irradiation

Abstract

New polymeric materials formation by controlling their properties is the primary and most challenging problem in developing a methodology for synthesizing a chosen technology and its use. The combined effect of high-energy electron radiation and tensile stress will cause a decrease in crystallinity and the breakage of chemical bonds in polyimide film macromolecules and is a new approach in their production technology. The effect of uniaxial tension and electron irradiation on the modification of polyimide film at room temperature was studied. Irradiation of the films caused an increase in the intensity of the IR spectrum by ~2–6 times and an increase in the width of the bands. The intensity in the range of 1700–3500 cm−1 increased, indicating an increase in the content of radicals as a result of irradiation. The amplitudes of the electron paramagnetic resonance signal from non-irradiated films increased from 3 × 103 to 5 × 103 as a result of uniaxial tension to fracture, indicating an increase in radicals in the material. The lines of the electron paramagnetic resonance spectrum shifted from 3475.0 cm−1 to 3512.5 cm−1, with a simultaneous decrease in the signal’s amplitude from 6 ×103 to 4 × 103, as a result of the electron irradiation of the films, followed by their subjection to tension. This was due to a decrease in the concentration of the radicals of the =N-H and –N-H2 groups until their disappearance and the formation of new ones.

Keywords

• polyimide
• films
• electron irradiation
• modification of macromolecules
• Infrared spectroscopy
• electron paramagnetic resonance