Electrochemical preparation and characterization of novel polyethylene/polyindene and polystyrene/polyindene composites

Abstract

In this study, the conducting homopolymer of indene and polyethylene/polyindene (PE/PIn) and polystyrene/polyindene (PS/PIn) composites have been electrochemically synthesized on platinum electrode in nonaqueous acetonitrile. The physical, electrochemical, thermal, and spectral properties of the synthesized PIn and their composites were investigated. The conductivities of PIn and the composites were measured with a four-probe technique. The conductivity of PIn was determined as 7.86 Â 10 À4 S/cm, whereas the conductivities of the PE/PIn and PS/PIn composites were determined to 6.42 Â 10 À5 S/cm and 5.64 Â 10 À5 S/cm, respectively. From Gouy scale magnetic susceptibility measurements, it was found that PIn and the composites had bipolaron natures. Fourier transform infrared spectra were taken to analyze the structural properties of PIn and the composites. The thermal properties of PIn and the PE/PIn and PS/PIn composites were investigated with thermogravimetric analysis, and it was found that they showed adequate thermal stability. According to the initial decomposition temperature among the composites, the composite including PE had the highest decomposition temperature with 450 C. The synthesized composites were different in aspect of morphology when compared to PIn.

Maghnite‐H+ Catalytic Synthesis and Characterization of Polyindenes and Oxidized Derivatives

“…This structure provides PIns a planar conformation, high glass transition temperature ( T g ) and interesting optical properties . Besides, the extended π‐conjugation, coplanarity and the presence of polarons have been proposed to be responsible of the electrical conductivity in this system, showing values ranging from 1.1*10 −5 to 7.9*10 −4 S cm −1 . Accordingly, PIns find potential application in areas such as solar energy systems, (photo)electronics, electrochromic devices, etc., apart from thermoplastics industry or gas separation .…”

“…On the other hand, chemical modifications of PIns via sulfonation or hydrogenation have been studied to obtain polymers for proton‐exchange membrane fuel cells (PEMFCs) and/or with interesting thermal properties, respectively. Furthermore, oxidized PIns were found interesting for a variety of applications, and PIns and their composites with inorganic particles have exhibited interesting electrorheological properties …”

“…In spite of these interesting properties, PIns show lower conductivity than conventional conducting polymers, limited thermal stability, and too rigidity and brittleness that hamper their suitability and processability for same applications. Accordingly, various studies have demonstrated that these features of PIns can be improved by blending or forming copolymers with coumarone, vinyl monomers, methylindene, pyrrole, styrenes, ethylene, polyoxomethylene, and others; or composites with Montmorillonite . In both PIns and indene‐based co‐polymers and composites, the different reactivity of atoms at indenyl groups and, therefore, the distinct indenyl coupling routes remarkably affect the indene spatial orientations and/or polymer structures and properties .…”

“…Various procedures to synthesize PIns can be found in literature, highlighting the electrochemical polymerization in CH 2 Cl 2 at room temperature; and chemical oxidative polymerization using different acidic/oxidizing catalysts and conditions: (i) AlCl 3 in CH 3 CH 2 Cl 2 , and cumyl methyl ether/TiCl 4 and CCl 3 COOH/ SnCl 4 in CH 2 Cl 2 , at low temperature (−20 to −65 °C); (ii) and FeCl 3 in CHCl 3 or concentrated H 2 SO 4 at ambient temperature 15–25 °C. All these processes to obtain PIn are based on the cationic polymerization mechanism and were carried out under inert atmosphere and anhydrous conditions. A low‐defective ideal planar structure was deduced for these PIns from their characterization with different techniques …”

“…All these processes to obtain PIn are based on the cationic polymerization mechanism and were carried out under inert atmosphere and anhydrous conditions. A low‐defective ideal planar structure was deduced for these PIns from their characterization with different techniques …”