Poly(2-methoxy-5-(2′-ethylhexyloxy)- p -phenylenevinylene) (MEH-PPV) has been prepared by a liquid/solid two-phase reaction.The liquid phase is tetrahydrofuran containing 1,4-bis(chloromethyl)-2-methoxyl-5-(2′-ethylhexyloxy) benzene as the monomer and a certain amount of tetrabutylammonium bromide (TBAB) as phase transfer catalyst (PTC).The solid phase is potassium hydroxide particles with diameters smaller than 0 5 mm.Gelation was found in the polymerization processes.As a result,MEH-PPV is partly soluble because of its large molar mass.Soluble MEH-PPV was obtained by using bromomethylbenzene as retardant regent.The molar mass of soluble MEH-PPV was measured to be 6 4×10 4g/mol.The Structure of polymer was identified by IR,Raman,UV/vis and PL spectra.A thin compact film of MEH-PPV can be formed by spin-coating and it emit a yellow light.
Poly3-[4-(4-pentyl-cyclohexyl)-phenyl]-thiophene(P3PhChPeT) films have been electrochemically synthesized by direct oxidation of 3PhChPeT in the mixed electrolyte of boron thrifluoride diethyl etherate(BFEE) and ethyl ether(EE)(4∶1,by volume).The oxidation potential of the monomer was measured to be 1.1 V(versus Ag/AgCl).P3PhChPeT in dedoped state is soluble in usual organic solvents such as tetrahydrofuran and chloroform,etc.The structure of the polymer films was studied by infrared,Raman and UV-visible spectroscopies.The molar mass of the polymer was measured to be about 3400 g/mol with polydispersity of 1.23. The fluorescent spectra showed a single broad band at 566 nm with excitation at 450 nm.The thermal analysis result indicated that this polymer had a high thermal stability with a decomposition temperature higher than 500℃.
Phenylthiophene (P2PT) has been electrochemically polymerized in pure boron trifluoride diethyl ether (BFEE) solutions or in a com p osite electrolyte of BFEE and trifluoroacetic acid (TFA).The addition of a certa in amount of TFA into BFEE lowered the oxidation potential of the monomer,accelerat ed the polymerization and also increased the current efficiency of the electrosy nthesis.The morphology and electrochemical behavior of as\|grown P2PT films were studied by scanning electron microscopy and cyclic voltammetry.Poly(2\|phenylth iophene) in dedoped state is soluble in usual organic solvents such as tetrahydr ofuran and chloroform,etc.Its structure has been examined by infrared,Raman and UV\|visible spectroscopies.The molecular weight of the polymer was measured to b e about 800 Da.Fluorescent spectral studies indicate the polymer is a blue\|gree n light emitter.
