Improving dispersion of multiwalled carbon nanotubes in polyamide 6 composites through amino‐functionalization

Abstract

The focus of this study is to investigate the state of dispersion of different treated multiwalled carbon nanotubes (MWNTs) in polyamide 6 (PA6). The MWNTs used in composites were grafted by 1,6-hexamethylenediamine (HMD) via acid-thionyl chloride to improve their compatibility with PA6 matrix. A microstructure transformation of MWNTs is found during the treatment process. Acidification makes the MWNTs compact and grafting HMD promotes the compact structure loose again. The MWNTs after different treatment were used to fabricate MWNTs/PA6 composites through melt blending. The dispersion of different MWNTs in PA6 was observed by a combination of scanning electron microscopy, optical microscopy, and transmission electron microscopy. The results show that the amino-functionalized MWNTs are dispersed more homogeneously in PA6 than the purified MWNTs, and the poorest dispersion is achieved for acid treated MWNTs. It is indicated that the loose structure and functionalized surface of MWNTs benefit the dispersion of MWNTs in PA6. In addition, the aminofunctionalization of MWNTs improves the compatibility between the MWNTs and PA6, resulting in stronger interfacial adhesion.

New strategies for the chemical characterization of multi-walled carbon nanotubes and their derivatives

“…[7,8] It has been reported in several cases that the modification of the surface of the carbon nanotubes with functional groups can help to disperse them, and may lead to enhancement of mechanical properties and electrical conductivity in different matrices. [9][10][11][12][13][14][15][16][17][18][19][20][21] In the case of the preparation of polymer nanocomposites based on carbon nanotubes, various researchers have reported an improvement of the mechanical properties when covalently surfacemodified carbon nanotubes were used. Compared with non-covalently functionalized CNTs, covalently functionalized ones can interact directly with the matrix system as the polymer bound to the CNT can transfer stress directly from the matrix to the CNT structure.…”

“…Compared with non-covalently functionalized CNTs, covalently functionalized ones can interact directly with the matrix system as the polymer bound to the CNT can transfer stress directly from the matrix to the CNT structure. [9,14,17,[22][23][24][25][26][27][28] However, the characterization of functionalized CNT is still difficult because of their high absorption of electromagnetic radiation across a broad spectrum [7,8]. This leads to a very low resolution for methods based on radiation like UV/Vis and IR spectroscopy.…”

Effects of processing and functionalization methods on nylon‐6,6 nanocomposites with Helical‐ribbon carbon nanofibers

“…On the other hand, CNFs treated in liquid phase form highly compacted granules after drying. These granules become agglomerates in the nanocomposites avoiding in a bigger extend the polymer introduction 25…”

Effect of Processing Conditions on the Mechanical Behavior of Amino Functionalized Nanotube Modified Glass Fiber Epoxy Composites

“…Further improvement in mechanical properties has been reported after the addition of amino functionalized CNT in PNC. 1,[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Besides, effective interfacial bonding between the composites individual constituents the properties of the composite materials is primarily dependent on the dispersion of CNT in the polymer matrix. Thus, at present the full potential of CNTs as reinforcement is still limited due to the non-homogenous dispersion of CNT as they exist as agglomerates and also due to poor interfacial interaction between CNTs and the polymer matrix.…”