Effects of 100 MeV O~(7+) ion beam irradiation on the optical, chemical and structural properties of NCO-terminated polybutadiene based liquid crystalline polyurethane

摘要

NCO-terminated polybutadiene based liquid crystalline polyurethane films were irradiated with O~(7+) ion beam at various fluences ranging 3 × 10~(10) to 1 × 10~(12) ions/cm2. Significant modifications in the structural, optical and chemical properties have been observed after irradiation. UV-visible spectra show a shift toward the higher wavelength regime after irradiation owing to the decrease in the band gap. FTIR spectra show the formation of NH_2 group and C=C bonds. The XRD spectra show the semi-crystalline nature of LCPU and with increasing fluence of irradiation a decrease in crystallinity is observed. However an increase in crystallinity at certain fluence followed by a decrease at the higher fluence of irradiation reveals the presence of secondary radiation induced crystallinity in LCPU.