私密直播全婐app免费大渔直播,国产av成人无码免费视频,男女同房做爰全过程高潮,国产精品自产拍在线观看

相關(guān)鏈接
聯(lián)系方式
  • 通信地址:加拿大魁北克省蒙特利爾
  • 郵編:無
  • 電話:(514) 848-2424 ext.5611
  • 傳真:
  • Email:zhibin.ye@concordia.ca
當(dāng)前位置:> 首頁 > 論文著作 > 正文
Covalent surface grafting of branched polyethylenes on silica nanoparticles by surface-initiated ethylene "living" polymerization with immobilized Pd-diimine catalysts
作者:Y. Zhang, Z. Ye*
關(guān)鍵字:無
論文來源:期刊
具體來源:Macromolecules
發(fā)表時(shí)間:2008年
We report in this article a new versatile surface-initiated ethylene “l(fā)iving” coordination polymerization technique for “grafting from” surface functionalization of silica nanoparticles with narrow-distributed branched polyethylene brushes of controllable length. The key to the success of this technique is the use of the acetonitrile Pd?diimine complex, [(ArN═C(Me)?(Me)C═NAr)Pd(CH3)(N≡CMe)]+SbF6? (Ar = 2,6-(iPr)2 C6H3) (1), which possesses unique immobilization and polymerization chemistry. In this technique, complex 1 was immobilized covalently onto acryloyl-functionalized silica particle surface by reacting with the surface-tethered acryloyl groups, giving rise to Pd?diimine chelate complexes covalently tethered on silica surface through an ester linkage. The tethered Pd?diimine chelate complexes catalyzed successfully surface-initiated ethylene “l(fā)iving” polymerization at 5 °C and ethylene pressure of 400 psi, leading to narrow-distributed branched polyethylene chains covalently tethered on silica surface through the ester linkage. The branched polyethylene brushes, after cleaved off from the silica particles, were found to possess narrow molecular weight distribution (polydispersity index of about 1.18) and have a linear increase of their number-average molecular weight and relative mass content with the polymerization time. The covalent grafting of polymer brushes was confirmed by using characterization techniques including nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). To the best of our knowledge, this represents the first report on the use of surface-initiated ethylene “l(fā)iving” coordination polymerization technique for surface functionalization of inorganic particles with polyethylene brushes.
主站蜘蛛池模板: 抚州市| 上饶县| 江陵县| 县级市| 瓦房店市| 曲靖市| 麦盖提县| 广德县| 天全县| 靖边县| 岳池县| 拉孜县| 湟中县| 永和县| 阿巴嘎旗| 平潭县| 扬中市| 福贡县| 平安县| 海兴县| 东港市| 鄂伦春自治旗| 阳城县| 介休市| 广河县| 萨迦县| 吴堡县| 广汉市| 怀柔区| 台湾省| 绥化市| 苏尼特左旗| 浮梁县| 南宫市| 霍城县| 金沙县| 潮州市| 洛宁县| 奉新县| 乐安县| 澳门|