We evaluated structural changes of poly (methyl-methacrylate) (PMMA) surfaces after and before vacuum ultraviolet (VUV)-irradiation using X-ray photoelectron spectroscopy (XPS) and Fourier trans form infrared spectroscope reflection absorption Spectroscopy (FTIR-RAS). When the PMMA films were irradiated with VUV light under reduced pressure of 10⁰Pa, XPS measurements showed that the O/C value decreased from 0.40 before VUV irradiation to 0.10 after irradiation at 10⁰Pa for 10 min. FT-IR spectral results indicated that C=O and ester peaks, which are parts of PMMA structures, were reduced by the VUV-irradiation. These results showed that oxygen-groups existed on the PMMA surface were decom posed by VUV-irradiation at 10⁰ Pa. However, these structural changes weren't observed when the PMMA was irradiated at 10³ Pa. Furthermore, we confirmed that C=O and ester peaks were reduced by VUV-irradiation at N₂ atmosphere. This result was the same as the case of VUV-irradiation at 10⁰ Pa. Although unirradiated PMMA was removed by toluene rinsing, the cured PMMA by VUV-irradiation at 10⁰ Pa could not dissolve. Utilizing these properties, we could prepare negative and positive-tone PMMA micropattems by VUV-light lithography through a photomask.

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In this paper, thermal oxidative degradation was performed using four kinds of polypropylene-impact copolymers (ImPP), and the relationship between degradation behavior and primary structure were inves tigated by ¹³ C-NMR, GPC and titration of hydroperoxide using potentiometry. It was found that the rate of degradation mainly depended on the ethylene content and did on tacticity in the same content. The information would be useful for synthesis of ImPP having a higher stability.

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