Effect of ϒ- irradiation and study of ϒ-induced physico-chemical changes in high performance thermoset obtained by double cycloaddition of munchnone and bis-maleimide

Abstract

ABSTRACT Techniques in polymer synthesis are taking different dimensions in the last few decades. Reversible-deactivation radical polymerization processes resulted in a wide range of polymeric architectures made from an almost infinite reservoir of functional building blocks. The concept of click chemistry revolutionized the way how polymer chemists approached synthetic routes. Among the few reactions that could qualify as click approach; the copper-catalyzed azide–alkyne cycloaddition reaction is in the front place. Whether click or not, cycloadditions are powerful tools for designing polymeric materials in a modular fashion, with a high level of functionality and, sometimes responsiveness. Thus we have developed an efficient synthetic platform for the preparation of a new class of polyimide-based high-performance thermosets (HPTs) based on the double 1,3-dipolar cycloaddition of munchnone with bis-maleimides. It is worth mentioning that this report is the first to deal with the changes in physico-chemical properties of HPTs obtained by cycloaddition reaction due to gamma irradiation. The polymers synthesized by this unique technique were irradiated with gamma doses in the range 10–300 kGy. The consequential effect of gamma radiation and the structural modifications induced on HPTs have been studied and discussed as a function of dose using different characterization techniques such as Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry-thermogravimetric analysis (DSC-TGA), Field Emission Scanning Electron Microscopy (FESEM) and UV-Vis Spectroscopy.