Synthesis And Charaterization Of Conjugated Polythiophenes

Polythiophene Conjugated polymers have important applications in the future, for example, it can be used as the active material for fabricating plastic solar cells and also be used as photochromic materials. Improving solublity, lowering band gap is the focus of the study in recent .Adding a long-chain substitutent in thiophene ring is a way to improve the solubility. In this paper thiophene derivatives with a thiophene ring containing -NHCH2CH2CH2CH3,-NHCH2CH2OH groups were designed and synthesized, and characterized by IR and H-NMR. 3-bromomethylthiophene used as raw materials for synthesing thiophene derivatives is synthesized and the syhthesing technology is optimized through orthogonal experiment. The results showed that the selectivity of the reaction vary with the level of different factors . the strength of the order is as follows: temperature >reaction time > the ratio of 3 - methylthiophene to NBS molar.In the condition of reaction temperature 70℃, reaction time 2h, the ratio of 3 - methylthiophene to NBS 0.9:1, the selectivity of 3– bromomethyl thio- phene is the highest, 0.524.band gap of polymer can been lowered by the introduction of the C = N within the structure of conjugated polymer to form DONOR / ACCEPTOR alternate. thiophene derivatives containing C = N group are designed and synthesized in order to obtain a polymer with lower band gap and characterized by IR and H-NMR. by che mical oxidative polymerization 10 kinds of poly-thiophene conjugated polymer are synthesized through self-polymerization and copolymerization. UV absorption spectra of the synthesized polymers is determined and is used to calculate the optical band gap. Stokes shift and fluorescence quantum yield of polymer is calculated from the data of fluorescence spectra . the polymer morphology is determined using scanning electron microscopy.