Proton and alpha particle induced changes in thermal and mechanical properties of Lexan polycarbonate

The thermal and mechanical properties of Lexan polycarbonate (PC) irradiated by 15 MeV proton and 40 MeV alpha particles with different fluencies have been investigated. The thermal decomposition temperature, thermal activation energy of decomposition, tensile strength, fracture strain, Young's modulus and average molecular weight of PC decreased after irradiation. The infrared spectroscopic results showed breakage of the carbonate site in PC after irradiation. The average surface roughness value of PC increased and it showed pores formation after irradiation. These changes in thermal and mechanical parameters were due to chain scission of C–O bond in PC after irradiation which is confirmed from infrared spectroscopic results. It was also showed that 40 MeV alpha particles induce more changes in thermal and mechanical properties of PC when compared to that of 15 MeV proton.

► The effect 15 MeV proton and 40 MeV alpha particles irradiation on PC was studied.
► The decrease in Td and Ea of PC shows thermal changes in PC.
► After irradiation mechanical properties and molecular weight of PC decreases.
► The average roughness value of PC increases after irradiation.
►  The changes in above properties may be due to chain scission in PC after irradiation.