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 magnetic 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 polystyrene, were in the range number-average molecular weights <(M)over bar (n)> = 2061-2544 and weight-average molecular weights <(M)over bar (w)> = 3347-3878. X-ray diffraction (XRD) analysis of the polymer showed semicrystalline structure. T-g = 57 degrees C, transition to a stable smectic mesophase at 115 degrees C and clearing point at 210 degrees C were revealed by differential scanning calorimetry analysis, optical microscopy observation and XRD of the annealed polymer.