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A series of new polyimides containing fluorinated alkoxy side chains are prepared from novel fluorinated alkoxy diamines. The dieletric constant at 1 kHz in the fluorinated polyimides decreases from 3.3 to 2.6 as fluorine content increases. The refractive index also changes from 1.58 to 1.48, dependent on the fluorine content. In addition, the fluorinated polyimides exhibit lower water absorption than the reference polyimides prepared from m‐phenylenediamine.

Corrosion products formed on copper plates exposed in urban, rural/coastal, and hot spring areas in Japan were characterized by X-ray photoelectron spectroscopy, X-ray diffraction ͑XRD͒, and coulometric reduction. The exposure tests were carried out for a month in summer. XRD patterns showed that hydrated copper sulfate ͓Cu 4 SO 4 (OH) 6 •H 2 O, posnjakite͔ and cuprite Cu 2 O were formed on copper surfaces exposed in urban and rural/coastal areas. The existence of sulfate salt agrees well with the XPS spectra. Sulfur dioxide and particulate sulfate such as ammonium sulfate and sea salt are both possible origins of this sulfate. In contrast, XRD revealed that the only corrosion product formed on the copper exposed in the hot spring area was cuprite Cu 2 O, although the amount of sulfur on the surface of this sample was the highest. Coulometric reduction analysis showed that there was copper sulfide Cu 2 S in corrosion products formed on copper exposed in the hot spring area. Posnjakite Cu 4 SO 4 (OH) 6 •H 2 O is initially formed in addition to cuprite Cu 2 O when copper is exposed in urban and rural/coastal atmospheres. This crystalline phase is located at and near the copper surface. Initially formed posnjakite Cu 4 SO 4 (OH) 6 •H 2 O may change to brochantite Cu 4 SO 4 (OH) 6 , which is a typical patina component that appears after further exposure.

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