SYNTHESIS, CHARACTERIZATION AND PROPERTIES OF A SOLUBLE POLYMER WITH A POLY(PHENYLENEVINYLENE) STRUCTURE

Soluble poly(2,5-dialkoxy-1,4-phenylenevinylene) has been prepared via Stille coupling reaction between 2,5-dialkoxy-1,4-diiodobenzene and E -1,2-bis(tributylstannyl)ethene in the presence of palladium complexes . Characterization of this material by means of H-1 and C-13 nuclear m agnetic resonance (NMR), ultraviolet/visible (UV/VIS) and infrared (IR ) spectra is described. Molecular weights, determined by means of gel- permeation chromatography (GPC) analysis and referred to standard poly styrene, were in the range number-average molecular weights <(M)over b ar (n)> = 2061-2544 and weight-average molecular weights <(M)over bar (w)> = 3347-3878. X-ray diffraction (XRD) analysis of tile polymer sho wed semicrystalline structure. T-g = 57 degrees C, transition to a sta ble smectic mesophase at 115 degrees C and clearing point at 210 degre es C were revealed by differential scanning calorimetry analysis, opti cal microscopy observation and XRD of the annealed polymer.