A comparative investigation between poly(1-ethynylpyrene) and poly(1,6-(3-ethynylpyrenylene)): Influence of the structure on the thermal, optical, electrochemical properties and conductivity

作者：Manuel Reyna Gonzalez Juan; Aguilar Martinez Martha; Garcia Concha Alberto; Palomar Celso; Rivera Ernesto^*

来源：Synthetic Metals, 2009, 159(7-8): 659-665.

DOI：10.1016/j.synthmet.2008.12.012

• Pyrene
• Polymer
• Thermal and optical properties
• Electrochemistry

A comparative investigation between trans-poly(1-ethynylpyrene) (trans-PEP) obtained chemically and poly(1.6-(3-ethynylpyrenylene) (E-PEP) prepared electrochemically was carried out. Thermal and optical properties of the polymers were studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and absorption spectroscopy. Electrochemical properties were evaluated by cyclic voltamperometry, in a 0.1 M Et(4)NClO(4)/THF solution at 10 mV/s, using a Pt disc as working electrode and Ag/AgCl as reference electrode. On the other hand, the conductivity of both polymers was measured in pressed pellet. Trans-PEP (T(10) = 369 degrees C) showed a higher thermal stability than its homologue E-PEP (T(10) = 256 degrees C). DSC of the polymers showed that trans-PEP exhibits a softening point at 330 degrees C, whereas E-PEP does it at 117 degrees C. Absorption spectra of the polymers revealed that trans-PEP exhibits two absorption bands at lambda = 336 nm and lambda = 580 nm due to the pyrene moieties and the highly conjugated polyacetylene main chain, respectively. By contrast, E-PEP showed only an absorption band at lambda = 358 nm followed by a tail, which reveals that this polymer possesses a lower degree of conjugation. Molecular modelling performed in short segments of these polymers confirmed this hypothesis. Regarding the electrochemical properties, trans-PEP showed an anodic peak at 1500 mV and a conductivity value sigma = 2.7 x 10(-2) S/cm, whereas E-PEP exhibited an anodic oxidation peak at 1670 mV and sigma = 8.4 x 10(-2) S/cm.

• 出版日期2009-4