Design, Synthesis And Structural Characterization Of Novel Hyperbranched Poly(phenylene Vinylene)

PPVs are widely studied conjugated polymer materials,But PPVs still have some shortcomings,for example,when the molecular weight of PPVs is large,they will become insoluable in the organic solvent,interaction between chains is prone,electronic transmission between chains lead to fluorescence quenching.Herein,five novel PPVs derivates were devised and successfully synthesized through Wittig or Gilch reaction.The three aspects were the focus of our attention.1.1,3,5-tri(bromomethyl)bezene and 2,5-Bis(chloromethyl)-1-methoxy-4-[(2'-ethyl-hexyl) oxy]-benzene are reactants,the polymers(P₁,P₂,P₃) were synthesized via Gilch reaction according to the ratio of reactants is 1:1.5,1:4 and 1:9 respectively.The polymers are soluble in common organic solvents.The polymers show the maximum absorptions in 503,493 and 490 nm in solution,respectively.The PL spectrum of P₁-P₃ in solution peaked at 567 nm.In comparison with the solution absorption spectra,the absorption bands of polymers P₁,P₂ and P₃ in thin films were red-shifted about 38,29.5 and 27 nm,respectively.The emission peaks of P₁-P₃ in thin films were red-shifted about 35,29 and 29 nm,respectively.The onset weights loss temperature of polymers were found to be 375,377 and 382℃for P₁,P₂ and P₃,respectively.2.1,3,5-tri(brominated phosphorus triphenyl methylene) benzene and 2-ethylhexyloxy -5- methoxybenzene-1,4-dialdehyde are reantants,the polymer P₄ was synthesized via Wittig reaction,the polymer P₁ was synthesized via Gilch reaction,the reactants of P₁ and P₄ are different,so the performance of P₁ and P₄ is distinct.The GPC-determined number-average molecular weights(Mn) for P₁ and P₄ are 1.76×10⁶ and 5.22×10⁴,with low polydispersity index(PDI) of 1.9 and 1.9,respectively.The maximum absorption band and the emission peak of P₁ were red shifted,compared with that of P₄,the onset weights loss temperature of polymers were found to be 375 and 373℃for P₁ and P₃,respectively.3.1,3,5-tri(brominated phosphorus triphenyl methylene) benzene and 4'-(5"-carbaldehyde-thiophen-2"-yl)phenyl)-thiophene-2-carbaldehyde are reantants, the polymer P₅ containing phenyl and thiophene in main chain was designed and synthesized via Wittig reaction.The maximum absorption bands of P₅.in chloroform solution and in thin film were at 440 nm and 375 to 550 nm,respectively.The emission peaks of P₅ in chloroform solution and in thin film were at 500-540 nm and 560-620 nm, respectively.The onset weights loss temperature were found to be 369℃for P₅. The reaction intermediate and polymers were characterized by ¹H-NMR,GC-MS, GPC and Elemental Analysis(EA).The optical properties,thermal property, electrochemical property were investigated,these polymers are soluble in common organic solvents and they have good thermal stability.These polymers may be promising materials for luminescent materials or solar cells.The application of resulting polymers to organic light-emitting devices(OLEDs) and Solar Cells was investigated successively.