Synthesis, characterization and properties of a soluble polymer with a poly(phenylenevinylene) structure

Abstract
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 1H and 13C nuclear magnetic resonance (NMR), ultraviolet/visible (UV/VIS) and infrared (IR) spectra is described. Molecular weights, determined by means of gelpermeation chromatography (GPC) analysis and referred to standard polystyrene, were in the range number‐average molecular weights Mn = 2061–2544 and weight‐average molecular weights Mw = 3347–3878. X‐ray diffraction (XRD) analysis of the polymer showed semicrystalline structure. Tg = 57°C, transition to a stable smectic mesophase at 115°C and clearing point at 210°C were revealed by differential scanning calorimetry analysis, optical microscopy observation and XRD of the annealed polymer.