scholarly journals Study of thermal properties and flame propagation on epoxy nanocomposites reinforced with carbon nanotubes

Author(s):  
Pedro Quirinus de Ruijter ◽  
Gabriel Benedet Dutra ◽  
Pedro Romano Durigan Neto ◽  
Robin Bahr Junor ◽  
Pedro Ferreira Zanetti
e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Young Seok Song ◽  
Jae Ryoun Youn

Abstract Rheological, mechanical, electrical, and thermal properties of epoxy nanocomposites containing carbon nanomaterials (CNMs) were investigated with different loading. Two kinds of CNMs - multiwalled carbon nanotubes (MWNTs) and carbon blacks (CBs) - were selected to examine the effect of their geometrical structure on various properties. Under sonication, MWNTs and CBs (0.5, 1.0, and 1.5 wt.-%) were mixed with the epoxy resin by using a solvent. Dispersion of the CNMs in the epoxy nanocomposites was characterized by means of transmission electron microscopy and field emission scanning electron microscopy. Carbon nanotubes (CNTs)/epoxy composites show significant differences from the CBs/ epoxy composites due to their high aspect ratio. It was found that the CNTs/epoxy composites exhibit non-Newtonian rheological behaviour, while the CBs/epoxy composites with the same weight content show Newtonian behaviour. The CNTs/ epoxy composites have better mechanical and thermal properties than the CBs/ epoxy composites. In the CNTs nanocomposites, the percolation threshold of electrical conductivity is found to be less than 0.5 wt.-%, which is too low to be obtained by using other carbon materials such as carbon fibre in polymer composites. Effects of CNM content on the various properties were also examined. As loading of the CNMs increased, improved results were obtained.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1234
Author(s):  
Arya Uthaman ◽  
Hiran Mayookh Lal ◽  
Chenggao Li ◽  
Guijun Xian ◽  
Sabu Thomas

The superior mechanical properties of multi-walled carbon nanotubes (MWCNTs) play a significant role in the improvement of the mechanical and thermal stability of an epoxy matrix. However, the agglomeration of carbon nanotubes (CNTs) in the epoxy is a common challenge and should be resolved to achieve the desired enhancement effect. The present paper investigated the thermal, mechanical, and water uptake properties of epoxy nanocomposites with surfactant-modified MWCNTs. The nanocomposites were prepared through the incorporation of different weight concentrations of MWCNTs into the epoxy matrix. Comparative analysis of neat epoxy and epoxy/CNT nanocomposites were conducted through thermal, mechanical, microscopic, and water uptake tests to reveal the improvement mechanism. The homogenous distribution of the CNTs in the epoxy was achieved by wrapping the surfactant onto the CNTs. The addition of surfactant-modified CNTs into the epoxy caused an obvious increase in the mechanical and thermal properties. This improvement mechanism could be attributed to the uniform dispersion of the CNTs in the epoxy matrix reducing the free volume between the polymer chains and restricting the chain segmental mobility, leading to strong interfacial bonding and an efficient load transfer capability between the CNTs and the epoxy matrix. However, the mechanical and thermal properties of the epoxy/CNT nanocomposite decreased owing to the agglomeration effect when the concentration of the CNTs exceeded the optimal percentage of 1.5%. Additionally, the CNTs could impart a reduction in the wettability of the surface of the epoxy/CNT nanocomposite, leading to the increase in the contact angle and a reduction in the water uptake, which was significant to improve the durability of the epoxy. Moreover, the higher weight concentration (2%) of the CNTs showed a greater water uptake owing to agglomeration, which may cause the formation of plenty of microcracks and microvoids in the nanocomposite.


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