The Research On Synthesis Of Alkoxy-substituted PPV And Its Derivatives

Polyphenylvinylene(PPV)and its derivatives is one of the most extensive research in photoelectric polymers recently. It can be the most promising conductive polymer which is used for the next generation solar cell materials, because of their easily manufacturing and good semiconductor properties like inorganic materials. However, it cannot be mass used because there are many disadvantages in pure PPV, such as too high bandgap, poor matching with the solar spectrum and too difficult solubility to become large scaled film.These performances can be improved through the main polymer chaincopolymerization, polymer side chain modification and polymer/inorganic nanocomposites. This thesis summarized research status of the polymer solar cells materials, particularly detailed in the synthesis, modification and application of PPV. Also it put forwards to the existing problems and prospected its application in the future.In this paper, on the basis of previous studies, we synthesized five different alkoxysubstituted PPV derivatives by the method of dehalogenating condensation reaction, through molecular design methods.Those PPV derivatives include poly(2-methoxy,5-butoxy)phenylenevinylene, poly(2-methoxy,5-pentyloxy)phenylenevinylene, poly(2-methoxy,5-octyloxy-phenylenevinylene),poly(2,5-dibutoxy-phenylenevinylene),poly(2,5-di-pentyloxy-phenylenevinylene). The spectral absorption properties of polymers were characterized by UV-Vis.Thestructures of each step production were characterized by FT-IR.Through the UV-Vis research, we characterized the property of the spectral absorption and we found that the absorption peak of infrared was moved and we also analyzed the reasons of it. Through calculated the energy gap of modified PPV, the result showed that the introduction of alkoxy can reduce the energy gap significantly. Comparing the thermal properties of different polymers through the DTA and TG analysis, the results showed that the materials have good thermal properties at room temperature. This paper alsostudied that the introduction of different groups on the polymer effected thedissolved properties, we found that the introduction of alkoxy can great improve the dissolved properties of polymer. In this paper, we explored that the infrared absorption, UV absorption and thermal properties of polymer were influenced by the introduction of nano-TiO2 on the polymer through preparing TiO2/PDBOPV nanocomposites, using SEM to view the morphology and the dispersion effect of the polymer.