Особливості процесу структуроутворення нанокомпозитів на основі поліетилену за його наповнення вуглецевими нанотрубками
| Autor: | Yu. V. Sherenkovskyi, R. V. Dinzhos, G. V. Ivanenko, V. G. Prokopov, Nataliia Meranova, V. L. Jurchuk, Nataliia Fialko, Raisa Navrodska |
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| Rok vydání: | 2018 |
| Předmět: |
chemistry.chemical_classification
полімерні нанокомпозити екзотерми кристалізації розмірність структуроутворення вуглецеві нанотрубки Materials science Nanocomposite Polymer nanocomposite Mixing (process engineering) Nucleation Polymer Polyethylene law.invention chemistry.chemical_compound Chemical engineering chemistry law lcsh:SD1-669.5 General Earth and Planetary Sciences lcsh:Forestry Crystallization Mass fraction General Environmental Science |
| Zdroj: | Науковий вісник НЛТУ України, Vol 28, Iss 6, Pp 74-80 (2018) |
| ISSN: | 2519-2477 1994-7836 |
| Popis: | The patterns of structure formation during crystallization of polymeric nanocomposites based on polyethylene filled with carbon nanotubes have been established. The effects of such factors as the mass fraction of the filler ω, the cooling rate Vt, and the method for obtaining composites have been revealed. Nanocomposites obtained by a method based on mixing the components in dry form and in the polymer melt were subject to review. A comparison of the experimental exotherms of crystallization for the investigated composites is performed with the indication methods of their preparation. Using exotherms of crystallization and the nucleation equation, data on the features of structure formation at the initial stage of crystallization of composites were obtained. It is revealed that at this stage there is a planar and three-dimensional mechanism of structure formation with a certain predominance of the latter. It is found that for the considered polymer nanocomposite materials, obtained by mixing the components in a dry form, this predominance is relatively small and slightly depends on the mass fraction of the filler. For composites obtained on the basis of mixing of components in a polymer melt, the predominance of a volume mechanism over a planar mechanism substantially is growing with an increase of the filler mass fraction. The authors analysed of the patterns of structure formation at the stage of crystallization in the bulk of composites as a whole under the assumption of the existence of two mechanisms of crystal formation. The first of them is associated with crystallization on polymer density fluctuations, the second with crystallization in which the filler particles play the role of its centres. It is defined that the mechanism of crystallization on polymer density fluctuations is volumetric when using both methods of composites production and does not depend on the rate of their cooling and the mass fraction of the filler. It is shown that the mechanism of crystallization on the filler particles is significantly influenced both by the method of obtaining composites and by the values of Vt and ω. It is found that when using the method of mixing components in dry form, this mechanism is volumetric. For nanocomposites obtained by mixing components in the polymer melt, it depends on the mass fraction of the filler and is transformed from volumetric to core with the increase in the mass fraction of the filler. |
| Databáze: | OpenAIRE |
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