Preparation of high‐performance carbon nanotube/polyamide composite materials by elastic high‐shear kneading and improvement of properties by induction heating treatment

Abstract

Polyamide 66 (PA66) nanocomposites were prepared by compounding carbon nanotubes (CNTs) using an elastic high‐shear kneading method, and the mechanism to understand their excellent properties was verified. In addition, we developed a microwave heat treatment that increases toughness quickly and at low cost. By combining 6.6 vol% or more of CNTs, PA66 with improved mechanical properties, such as higher elastic modulus and yield strength, was achieved, making it possible to obtain a composite having excellent high‐temperature characteristics that does not melt even at a temperature above the melting point. These effects appeared to be due to defibration of CNT aggregates and isolation and dispersion in PA66. A lamellar crystal of PA66 grows around the CNT, forming an interphase. The higher performance appeared to be attributable to a continuous three‐dimensional structure in which CNTs are bound via the interphase, and the improvement of the elastic modulus of the composite material was tentatively ascribed to a Halpin‐Tsai model in which the size of the unit cell of the three‐dimensional structure is introduced. The resulting CNT/PA66 composite materials are superior not only in performance but also in price.

Application of Solution Blow Spinning for Rapid Fabrication of Gelatin/Nylon 66 Nanofibrous Film

“…Figure 2b shows the XRD results of the GA, PA66 films and GA/PA66 films with various weight ratios. PA66 has two obvious diffraction peaks at around 2θ = 20.1° ascribed to the interchain hydrogen bond plane of the amide group [29] and 2θ = 23.7°, which is similar to the results of Noguchi's study [39]; whereas gelatin had a broad diffraction peak at 2θ = 19.2°, suggesting a low crystallinity of GA. For the GA/PA66 composite films, two diffraction peaks appeared between 20° and 25°, which were corresponding to the two characteristic peaks (α1 and α2) of the α-crystalline form of PA66 [38]. It was noticeable that the intensity of the peaks of the GA/PA66 composite film was enhanced compared to the pure GA film, suggesting that the crystallization of the GA/PA66 composite films was advanced with the addition of PA66.…”

Residual compressive strength of polyamide fiber‐reinforced epoxy composites after low‐velocity impact

“…[1][2][3][4][5][6][7][8][9][10] Glass-fiber, carbon-fiber and basalt-fiber composites achieved by mixing fibers with polymeric resin can be demonstrated as the most common examples. [11][12][13][14][15][16] These fiber-reinforced composite materials are extensively utilized in many engineering fields such as aerospace, aviation and automobile due to their high strength, lightweight, stiffness, resistance to environmental and corrosive factors, design originality and production advantages. [3,10,17,18] Especially, the use of fiber-reinforced plastics has been growing in the automotive field due to their high strength, good damping, stiffness and lightweight features.…”