Poly(2-(2-carboxylic acid-benzamido)-phenylenevinylene)(CB-PPV)光電高分子與其共聚物之合成及性質探討

Abstract

本論文利用Phthalic anhydride在苯環側邊形成Phthalimide保護基，接著使用UV燈進行光溴化反應，合成2-phthalimido-1,4-bis(bromomethyl)-phenylene單體，再利用Gilch聚合法，成功聚合出具有醯胺及羧酸側基之Poly(2-(2- carboxylic acid-benzamido)-phenylenevinylene) (CBPPV)。CB-PPV為聚電解質，但可溶於有機溶劑中進行塗佈形成淡黃色薄膜。此carboxylic acid-benzamido側基造成UV與PL之強烈藍位移，降低CB-PPV在可見光範圍之吸收。另外，羧酸側基可達到近似於自摻雜效果，提高CB-PPV薄膜導電率到達10-6S/cm等級。因此，新合成之CB-PPV有機會製作成透明導電薄膜。另外，將發藍光的CB-PPV與紅光的MEH-PPV共聚合，比較各種比例共聚物之UV與PL性質。由初步研究顯示共聚物亦可能應用在太陽能電池。

2-phthalimido-1,4-bis(bromomethyl)-phenylene monomer for a novel poly(2-(2-carboxylic acid-benzamido)- phenylenevinylene)(CB-PPV) was synthesized through the photo-bromination under UV exposure. CB-PPV has both amido and carboxylic acid side groups. Thus, CB-PPV is a polyelectrolyte, but can be dissolved into the organic solvents to form a light yellow thin film by spin-coating. The carboxylic acid-benzamido side group induces strong blue shift to the UV and PL spectra of PPV, and thus decreases the absorption in visible light. In addition, the carboxylic acid in side group exhibits a similar effect of self-doping. Accordingly, the conductivity of CB-PPV thin film can achieve an order of 10-6 S/cm. Therefore, the CB-PPV introduces a chance for fabricating a transparent conducting thin film. Besides, the copolymers of blue emissive CB-PPV and red emissive MEH-PPV in different composition ratios are synthesized and their photoluminescence properties are basically dependent on their compositions. Furthermore, the preliminary study reveals that the copolymers can also be applied to solar cells.