engleski

The influence of titanate nanotubes on thermal and mechanical properties of epoxy nanocomposite

Titanate nanotubes and nanoribbons (NaTiNTs and NaTiNRs) have been a subject of intensive research for possible applications in photocatalysis, sensors, and lithium ion batteries, due to their interesting physical properties. These materials are also interesting for the preparation of polymer nanocomposites as well, since their Young modulus is comparable to that of carbon nanotubes and the fact that they can be synthesized in large quantities with high yields. NaTiNTs were prepared by hydrothermal method and functionalized with 3-(aminopropyl) triethoxysilane (APTES). Functionalized NaTiNTs were used to prepare epoxy-based nanocomposites with three different wt. % of nanofillers (1, 3 and 5 wt. % per epoxy). The thermal and mechanical properties of prepared nanocomposites were studied by differential scanning calorimetry (DSC), thermal gravimetric analysis, (TGA) and dynamic mechanical analysis (DMA). Combustion properties were studied by cone calorimetry at an imposed heat flux of 50 kW/m2. The results showed that the glass transition temperature increased from 72°C to 81°C. Storage modulus increased for 10% at 3 wt.% nanotubes and did not change with further addition. Significant reduction of the Heat Release Rate (HRR), depending on the inorganic particles loading was observed. The peak value for HRR was reduced by about 40% compared to the pristine epoxy resin, while ignition time and total heat release are not significantly affected by the presence of the inorganic particles. This behaviour is explained by the surface accumulation of inorganics on the surface of the specimen during the early stages of combustion, leading to the formation of a ceramic layer able to slow down the combustion process. Such surface layer may act as a protection for underlying polymer, by the partial shielding/reradiation of incoming heat flux.

Titanate ; Nanotubes ; Nanoribbons ; Epoxy ; Nanocomposite

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