In order to elucidate the degradation process of epoxy resin paint film, bisphenol A/epichlorohydrin type epoxy clear films were coated on the sample tube of ESR (X-Band) and they were exposed under ultra-low pressure mercury arc lamp (Main wave length : 254 nm) so as to detect radical by ESR equipment. A stable radical was detected and was identified as phenoxyl radical of g=2.0042. The change of FT-IR spectra of clear film exposed for 24 hours under the lamp was measured. In the photo-degradation process of resin film, phenoxyl radical was induced. Then, quinonoid and aldehyde compounds appeared gradually while various low molecules were evaporated. White paints using four kinds of surface treated titanium dioxides were prepared in the same epoxy/butylated urea system. Relative quantity of phenoxyl radical and gloss retention for four kinds of painted film were measured after exposing under the lamp. As the results, it was pointed out that the more the relative quantity of phenoxyl radical, the lower the gloss retention.
The wetting of an oily material on a nonionic surfactant solution have been studied in terms of the contact angle of an oil droplet on the nonionic surfactant solution, surface tension and the interfacial tension. Polyoxyethylene hexadecyl ether (C16H33-(0-CH2CH2) n-OH, n=5. 5-20) was used as a nonionic surfactant. Normal dodecane was used as a non-polar oily material. Oleic acid, oleyl alcohol, and corn oil were used as a polar oily material. The n-dodecane spread on the surfactant solution, in spite of the concentrations of surfactant like as duplex film. On the other hand, oleic acid, oleyl alcohol, and/or corn oil were dependent on the concentration of surfactant : in the case of a lower concentration of nonionic surfactant, although a large portion of the polar oily material formed a oil droplet in a state of lens, a part of it spread, and then penetrated into a surfactant layer at liquid-gas interface; in the case of a higher concentration of nonionic surfactant, the polar oily material formed the above-mentioned oil droplet without spreading onto the liquid-gas interface. This may be due to the fact that the state of adsorption of the nonionic surfactant molecule is dependent on the concentration and hydrophile-lipophile balance (HLB).
The pyrolysis of the silica gels treated with C5 alcohols, i. e., 1-pentanol, 1-2-methyl-1-butanol, d-2-pentanol, 1-2-pentanol and cyclopentanol and the pyrolysis of these alcohols in gaseous phase or over silica gel have been investigated through the identification and analysis of these products by means of the quadrupole mass spectra or of the gas chromatograph-quadrupole mass spectra. Both dehydration and dehydrogenation of the alcohols proceed simultaneously for the pyrolysis of those alcohols in gaseous phase. Since dehydration proceeds selectively for their pyrolysis over silica gel at lower temperature than that of their pyrolysis in gaseous phase, it is recognized that silica gel proceeds catalytically dehydration reaction of the alcohols. At higher temperature, both dehydration and dehydrogenation reactions proceed. The main products of pyrolysis of the surface-treated silica gels were observed to be water, alcohols used and the corresponding olefins. The evolution of water observed under 130°C and the alcohols observed under 250°C were considered to be due to the elimination of physisorbed ones. Although the olefines and water were observed at the range of 250°C and 500°C, the ratio of the amount of water to that of olefines was not constant against the decomposition temperature. Thus, these pyrolysis products were recognized to be formed under the different reaction mechanism. These surface groups are perceived to be combined chemically with substrate in the form of>SiOR.