Polycondensation of Hexamethylenetetramine in Anhydrous Acid Media as a New Approach to Carbyne-Like Materials and Its Application as Dispersant of Carbon Materials

Alyona V Gerasimova,Olga V Alekhina,Alexander V Melezhik,Jesús Iniesta,Leticia García-Cruz,Aleksey G Tkachev

doi:10.3390/c5030054

Alyona V Gerasimova, Olga V Alekhina + Show 4 more

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https://doi.org/10.3390/c5030054

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Abstract

Aminocumulene (AC), a technical name that results from the hexamethylenetetramine polycondensation in anhydrous sulfuric acid, was successfully performed toward the synthesis of oligomeric cumulenic compounds made up of carbyne-like (=C=C)x fragments as a main moiety together with amino endcapping groups. The tentative mechanism for the synthesis of the soluble and insoluble AC likely included the participation of carbene species as an intermediate. Spectral properties obtained from UV-Vis, infrared, and Raman spectroscopies, and surface chemistry analysis through X-ray photoelectron spectroscopy of the soluble AC confirmed the presence of a mixture of linear and branched aminocumulene-based oligomers. AC displayed high performance as a dispersant and stabilizer agent of both multi-walled carbon nanotubes and graphene in aqueous solutions after powerful insonation treatment under controlled temperature compared to the most commonly used dispersant agents. Thereby, AC is vitally important for the preparation of carbonaceous materials based on nanoinks in a wide variety of fields.

Highlights

The nature of polymeric substances with a cumulated double-bond chain with both virtually equal double and alternating triple and single carbon–carbon bonds are well-known in the literature [1].Such structures are assumed for the carbyne that is a new allotropic modification of carbon [2,3,4].A review of the synthesis methods for such compounds was reported in [5]
The experiments showed that when using concentrated sulfuric acid (95% H2 SO4 and 5% water) as a reaction medium instead of 5 wt% oleum (95% H2 SO4 and 5% SO3 ), the AC yield decreases remarkably
Taking into account the complexity of carbyne-like compounds synthesis according to the reported literature [11], we described here a novel, facile chemical procedure using HMTA as a precursor for AC

Summary

Introduction

The nature of polymeric substances with a cumulated double-bond chain with both virtually equal double and alternating triple and single carbon–carbon bonds are well-known in the literature [1].Such structures are assumed for the carbyne that is a new allotropic modification of carbon [2,3,4].A review of the synthesis methods for such compounds was reported in [5]. The nature of polymeric substances with a cumulated double-bond chain with both virtually equal double and alternating triple and single carbon–carbon bonds are well-known in the literature [1]. Such structures are assumed for the carbyne that is a new allotropic modification of carbon [2,3,4]. Compounds with short fragments of such chains are synthesized, and their structures are proved by physico-chemical characterization These compounds contain terminal groups such as alkyl, aromatic, halogenated, or alkoxy groups, depending on the synthesis method [5]. The synthesis of carbyne and related compounds is often very complex and unsuitable for upscaling, thereby hampering their practical application

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