Synthesis and Characterization of Novel Conjugated Poly2,2’-bis(trifluoromethyl)-4,4’-biphenylenevinylene

• Main Authors: Jyh-Jong Ju, 朱志忠
• Other Authors: Jyh-Chien Chen
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/00317558064355025892

碩士 === 國立臺灣科技大學 === 高分子系 === 96 === The objective of this study is to introduce twisted biphenyl structure containing trifluoromethyl groups at 2 and 2’ positions into the main chain of the π-conjugated polymer. The incorporation twisted biphenyl structure has been proven to enhance the solubility of polyimides effectively. To our knowledge, this is the first attempt to improve the poor solubility of π-conjugated polymers by this method. The novel π-conjugated polymers in this study were synthesized by using three new compounds, 2,2’-Bis(trifluoromethyl)-4,4’-biphenyldicarbaldehyde(10) 、2,2’-Bis(trifluoromethyl)-4,4’-bis(chloromethyl)biphenyl(12) and 2,2’-Bis(trifluoromethyl)-4,4’-bis(methylenediethyl phosphate)biphenyl(13) , through Gilch and Horner-Emmons reactions. The formed polymers have relatively high molecular weights in the range of 7200 to 13500 (measured by GPC in DMAc and calibrated by polystyrene standards) and inherent viscosity 1.07 (determined in NMP, 0.5 g / dL at 30 ℃). These polymers exhibit excellent solubility in common organic solvents such as NMP、DMAc and DMF. This is particularity unique since the enhanced solubility is not achieved by the introduce of long , branched aliphatic ether side groups, which are widely used to improve the solubility of π-conjugated polymers. The formed polymers shows the glass transition at 204 ℃(by DSC ) , and the 5% decomposition temperature at 512 ℃. From Uv-visible spectrometric analysis, the maximum absorptions occur at the wavelength λmax between 321 and 341nm. The energy gap (Eg) calculated by the onset wavelength (λonset ) ranges from 3.27 to 3.41eV. From photoluminesce spectrum, the formed polymer shows maximum emission at wavelength 400nm, in NMP solution when excited by 345nm light.