Abstract

Lexan polycarbonate films were irradiated by UV radiation at wavelength $$ \lambda $$ = 250 nm under different time exposures of 1, 2, 4, 6 and 7 h. Structural, optical and mechanical modifications were studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), UV–Visible spectroscopy, impedance analysis, tensile testing and rheometry methods. The crystallite size and percentage of crystallinity were found to decrease upon irradiation as was studied by XRD. It indicated that polymer was moving towards more disordered state after irradiation corroborating DSC results. FTIR Study showed the carbonate linkage is the radiation-sensitive linkage and benzene ring does not undergo any change after irradiation. SEM results showed the formation of pores after irradiation. The atomic force microscopy measurements revealed that the average roughness of the film increased after being irradiated. The glass transition temperature was observed to decrease after irradiation as revealed by DSC measurement. UV–Visible spectra showed decrease in optical band gap after irradiation due to chain scission in the Lexan polycarbonate. Plot of AC conductivity versus log (f) displayed a sharp increase in conductivity at higher frequencies and dielectric constant/loss was observed to change with the irradiation time. The mechanical properties and average molecular weight of Lexan polycarbonate decreased after irradiation, while the average number of chain scissions per original polymer molecule increased with increase in time of exposure.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.