Broadband far-infrared absorption spectra were measured for sheets of low density polyethylene (LDPE), containing various contents of three kinds of phenol-type antioxidants, BHT, Irganox 1010, and Irganox 1330. Each antioxidant exhibits its characteristic spectrum with various peaks, most of which show a monotonic increase in intensity with the increase in content of antioxidant. Therefore, we ca...Show More
We added each of seven different kinds of anti- oxidants to a low-density polyethylene sheet and measured their Fourier-transform mid-infrared (FT-MIR) and FT-far-infrared (FT-FIR) absorption spectra. As a result, it has become clear that each antioxidant in general gives a clear specific FT-FIR spectrum even when the FT-MIR spectrum of the corresponding antioxidant is very similar to the spectra ...Show More
Terahertz absorption spectra were measured for nine kinds of antioxidants. The spectra were also measured for low-density polyethylene sheets that contain each antioxidant with different contents. As a result, a fingerprint spectrum appears for each antioxidant, from which the antioxidants become distinguishable and their contents can be estimated.Show More
Flame-retardant ethylene-propylene-diene copolymer (FR-EPDM) with the same additives as those used in nuclear power plants was analyzed by terahertz (THz) and infrared (IR) absorption spectroscopy, before and after the irradiation by γ-rays. As a result, it has become clear that THz spectroscopy can indicate the degradation of the FR-EPDM samples better than IR spectroscopy. Namely, the THz spectr...Show More
