ポリ(N-ビニルカルバゾール) 化学特性,用途語,生産方法
解説
ポリ(N-ビニルカルバゾール),重合体はラジカル重合,イオン重合などで得られる.ガラス転移温度 Tg84 ℃.軟化温度100~150 ℃.密度1.20 g cm-3(23 ℃).電気的性質がポリスチレンと同程度で軟化点が高い.この重合体の特徴はその光伝導性にある.絶縁体(電気伝導率 10-16~10-18 Ω-1 cm-1)であるが,波長約400 nm 以下の光を照射すると,光伝導性を示す.一般に,この重合体のような大きなπ電子系の置換基が主鎖に直接結合している重合体は,無定形部分でも一本のポリマー鎖はかなり規則的な構造をとっていて,キャリヤーは,このポリマー鎖に結合しているもっとも近い置換基の間を容易にホッピング移動できると考えられている.色素,そのほかの光増感剤を加えると,普通の紫外光あるいは白色光下で光伝導性を示すようになる.現在,この性質を利用して,電子写真や静電気記録などに広く実用化されている.
森北出版「化学辞典(第2版)
製造
ビニル基の位置により種々のビニルカルバゾールがあるが,重合体として重要なのは,次に示すN-ビニルカルバゾールの重合体ポリ(N-ビニルカルバゾール)であるポリ(N-ビニルカルバゾール).
化学的特性
off-white crystalline powder
使用
PVK:graphene oxide composite can be used as a hybrid film which can be coated on silica substrate for the fabrication of organic field effect transistors (OFETs). It can also form a nano-composite film with carbon nanospheres (CNS) which can be potentially used in supercapacitors and sensor based applications.
定義
ChEBI: A macromolecule composed of repeating 9-ethylcarbazole units.
製造方法
N-Vinyl carbazole may be obtained from phenylhydrazine and cyclohexanone by the following route:
![説明図](https://www.chemicalbook.com/NewsImg/2022-03-11/20220127135114.jpg)
The second step in this synthesis is an example of the Fischer indole synthesis.
Carbazole also occurs in coal tar.
Poly(vinyl carbazole) is produced by adiabatic bulk polymerization under
nitrogen pressure using azobisisobutyronitrile and di-tert-butyl peroxide as
initiators. Heating to 80-90??C causes an onset of polymerization and a rapid
increase in temperature. After the maximum temperature has been reached
the mass is cooled under pressure.
Poly(vinyl carbazole) is a very brittle material with a high softening point
(about 195??C Vicat). It is insoluble in most organic solvents except aromatic
and chlorinated hydrocarbons and tetrahydrofuran. The polymer is difficult
to mould, requiring high process temperatures, namely about 300??C for
injection moulding and 250??C for compression moulding. More usually the
material is cast as thin film from solution. The most significant property of
poly(vinyl carbazole) is its high photoconductivity and this has resulted in
widespread use of the polymer in electrostatic dry-copying machines. When
an electrostatic charge is applied to the polymer in the dark it discharges to
an equilibrium value but when the polymer is illuminated almost complete
discharging occurs. This phenomenon is used to create a latent electrostatic
image which is then developed by transferring the charge to the toner.
Poly(vinyl carbazole) also has good electrical insulation characteristics which are maintained over a wide range of temperature and frequency. On account
of these characteristics, the polymer has been used as a capacitor dielectric, but this application is now of minor importance.
一般的な説明
Poly(9-vinylcarbazole) (PVK) is a conductive polymer which is mainly used as a hole transporting medium at high efficiencies with low driving voltage. It can also be used as an anode for hole injection and can act as an effective charge transferring gate by co-doping it with organic dyes.
純化方法
Precipitate it seven times from tetrahydrofuran with MeOH, with final freeze-drying from *benzene. Dry it under vacuum.
ポリ(N-ビニルカルバゾール) 上流と下流の製品情報
原材料
準備製品