Peculiarities of the initial stages of carbonization processes in polyimide-based nanocomposite films containing carbon nanoparticles

I.V Gofman,V.E Yudin,M Zaloudkova,M Cerny,M.Ja Goikhman,K Balik,Eugen Stulz

doi:10.1080/23312009.2015.1076712

I.V Gofman, V.E Yudin + Show 5 more

Open Access

https://doi.org/10.1080/23312009.2015.1076712

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Abstract

AbstractCarbonization of the polyimide-based composite films containing carbon nanoparticles, namely nanofibers and nanocones/disks, in the temperature range 500–550°C was studied and the kinetics of the initial stage of carbonization and the effect of the filler on the mechanical properties of the carbonized films were evaluated. Two polyimides (PIs) characterized by different macrochains’ rigidity and different degrees of ordering of the intermolecular structure were used. The character of the nanofiller’s action on the kinetics of the carbonization process depends on the heating rate. In this work, the intensity of the destruction of the PI matrix of the composite films was shown to be slightly higher than that of films of the same polymers with no filler. The introduction of the carbon nanoparticles into both PIs provokes the increase in the ultimate deformation values of the partially carbonized films, while the carbonization of the unfilled PI films yields the brittle materials. The Young’s modulus ...

Highlights

One of the promising directions of the progress in contemporary materials science, which makes it possible to obtain thermally stable and durable materials with low density, is the development of carbon materials
The kinetics of the carbonization process of the PI and composite films The first question to be clarified during this work concerned the influence of the nanoparticles, introduced into the PI matrix, upon the kinetics of the carbonization process
The kinetics of the carbonization of both the PI and composite films studied are strongly dependent upon the temperature–time regime of this process

Summary

Introduction

One of the promising directions of the progress in contemporary materials science, which makes it possible to obtain thermally stable and durable materials with low density, is the development of carbon materials. The important problem of modern polymer science is to select the types of polymer matrices that, under the appropriate thermal treatment, can be converted into the graphite-like carbon materials with the optimal structure and properties. The processes of the initial polymers transformation into the carbon materials take place in the wide temperature range of 2,700–2,800°C, but the important role in the formation of the final material with optimal characteristics belongs to the initial stage of the heat treatment of the PI precursor in the range of 500–700°C It was shown (Dobrovol’skaya, Mokeev, Sazanov, Gribanov, & Sukhanova, 2006; Doyama et al, 2011; Gribanov, Sazanov, & Mokeev, 2002) that deep structural and chemical transformations of the starting PIs occur in this temperature range to form the “green product” of future graphite-like materials. The impact of carbon nanoparticles of different types on the thermally stimulated processes, which pass in the PI-based composite films at the early stages of carbonization, and on the properties of these films in the carbonized state are investigated in this work

Experimental

Results and discussion

Conclusions