{"title":"Polyaddition of Bifunctional Isoprene Prepolymer Terminated with Hydroxy Groups and Diisocyanates.","authors":"H. Kouzai, T. Mitsumata","doi":"10.1246/NIKKASHI.2002.409","DOIUrl":"https://doi.org/10.1246/NIKKASHI.2002.409","url":null,"abstract":"ヒドロキシ基を両末端に結合したイソプレンプレポリマーがナトリウム-ナフタレンを開始剤としてイソプレンの溶液重合を行って,まずリビングプレポリマーとし,さらに乾燥酸素を通じて約75%の収率で得られた.このプレポリマーの分子量は1300–1500であり,1分子当たりのヒドロキシ基数は2.0–2.15であった.また,このプレポリマーのジイソシアナートによる重付加について若干検討した.反応溶媒としては,アニソール以外にN,N-ジメチルホルムアミドとジメチルスルホキシドが使用できる.得られたポリマーは黄色のスポンジゴム状で,一般の有機溶媒には不溶である.また,ガラス転移温度は73–78 °Cであった.","PeriodicalId":19311,"journal":{"name":"Nippon Kagaku Kaishi","volume":"30 1","pages":"409-413"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91349704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Nakayama, T. Terada, S. Kakita, Shinji Imai, M. Sakamoto
{"title":"Perovskite Oxide LaCoO3 Prepared by Solid-state Reaction, Pyrolysis of a Co-Precipitated Precursor or Pyrolysis of a Heteronuclear Complex.","authors":"S. Nakayama, T. Terada, S. Kakita, Shinji Imai, M. Sakamoto","doi":"10.1246/NIKKASHI.2002.485","DOIUrl":"https://doi.org/10.1246/NIKKASHI.2002.485","url":null,"abstract":"The perovskite oxide LaCoO3 was synthesized by three different preparative methods i.e., the calcination of a mixture of La2O3 and CoO (La–Co–O) and pyrolysis of a co-precipitated precursor (La–Co–ox), La2 (C2O4)3 · xH2O + CoC2O4 · yH2O, and a heteronuclear complex (La–Co–CN), La[Co(CN)6] · 5H2O. The obtained powders were characterized by thermogravimetric analysis, infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy and specific surface area measurements. The formation of LaCoO3 single phase is clearly recognized for La–Co–O, La–Co–ox and La–Co–CN at temperatures above 1000, 1200 and 600 °C, respectively. The nano-sized LaCoO3 powder was obtained at low temperatures by pyrolysis of La–Co–CN. The mean particle diameter of La–Co–CN calcined at 600 °C for 2 h was 72 nm.","PeriodicalId":19311,"journal":{"name":"Nippon Kagaku Kaishi","volume":"92 1","pages":"485-488"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76394556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Flow Characteristics and Saline Wedge of the Density Flow in a Tidal River.","authors":"H. Tatsumoto, J. Park, M. Aikawa","doi":"10.1246/NIKKASHI.2002.77","DOIUrl":"https://doi.org/10.1246/NIKKASHI.2002.77","url":null,"abstract":"塩水くさびが存在する流れの流動特性をは握するために長方形断面の開水路を用いて塩水くさびの発生と流動の実験を行った.塩水くさびは全体的に安定して目視観測を容易にしたため,その界面層の観測は可視化手法で行った.実験の結果,塩水くさびは十分に再現され,塩水くさびの先端は相対密度と上流部の流量によってその形状が変化することが認められた.下流部の淡水深の厚さはリチャドーソン数に依存性を持っていることがわかった.また,はく離点付近の希釈の度合は密度層内のFioとの関数で表示できた.","PeriodicalId":19311,"journal":{"name":"Nippon Kagaku Kaishi","volume":"5 1","pages":"77-83"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90539544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yasuyuki Suzuki, Jun Li, Y. Maekawa, Masaru Yoshida, K. Maeyama, N. Yonezawa
{"title":"Conversion of Hydrophilic Surface of Poly(ethylene terephthalate) Film to Hydrophobic One under Hydrophilic Conditions.","authors":"Yasuyuki Suzuki, Jun Li, Y. Maekawa, Masaru Yoshida, K. Maeyama, N. Yonezawa","doi":"10.1246/NIKKASHI.2002.255","DOIUrl":"https://doi.org/10.1246/NIKKASHI.2002.255","url":null,"abstract":"The hydrophilic surface of poly(ethylene terephthalate) (PET) film, obtained by partial hydrolysis, was converted to hydrophobic one under dry air, saturated water vapor atmosphere, nitrogen, and vacuum at temperatures ranging from 0 to 80 °C. The hydrophilicity of the surface increased significantly faster under the saturated water vapor although it was the most hydrophilic in the examined conditions. From the dependence of the absolute temperature on the rate of hydrophilicity change for each storage condition, a discontinuous point at ca. 50 °C was observable only under the water vapor condition. This relation indicates that the appreciable acceleration of the hydrophilicity change on the surface under the hydrophilic condition might be resulted from the increase of the surface mobility due to the water adsorption on the PET surface.","PeriodicalId":19311,"journal":{"name":"Nippon Kagaku Kaishi","volume":"69 1","pages":"255-259"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83196887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}