Improvement of interfacial properties of carbon fiber‐reinforced poly(phthalazinone ether ketone) composites by introducing carbon nanotube to the interphase

Abstract

This article aims to improve interfacial properties of carbon fiber-reinforced poly(phthalazinone ether ketone) (PPEK) composites by means of preparing carbon nanotube (CNT)/carbon fiber hybrid fiber. XPS was used to characterize the chemical structure of unsized carbon fiber and SEM was used to observe the surface topography of carbon fibers. Specific area measurement, dynamic contact angle, and interfacial shear strength (IFSS) testing were performed to examine the effect of CNT on the interfacial properties of carbon fiber/PPEK composites. By the introduction of CNT to the interphase of carbon fiber-reinforced PPEK composites, an enhancement of IFSS by 55.52% was achieved. Meanwhile, the interfacial fracture topography was also observed and the reinforcing mechanism was discussed. POLYM. COMPOS., 36:26-33, 2015. V C 2014 Society of Plastics Engineers INTRODUCTIONCarbon fiber-reinforced thermoplastic (CFRTP) composites have recently attracted increasing attention mainly due to their combination of high performance, good processability, and potential recyclability. These advantages together have made these composites an attractive contender in a wide range of applications including aerospace, automobile, marine, military, etc. [1][2][3][4][5][6][7]. Accordingly, there arise the attempts at tailoring the material properties of CFRTP composites to serve the specific needs of these applications. One of ways to achieve this is to alter the fiber-matrix interface, which has been well established as crucial in controlling composite performance due to its role in the stress transfer efficiency between the fiber and the matrix [8][9][10].Since carbon fibers are basically brittle, they are always sized with a thin coating of a prepolymer or resin [11]. The sizing agents of carbon fibers, to a large extent, determine the interfacial properties of carbon fiber composites. The wetting performance of carbon fiber and interfacial strength of fiber composites can be both improved by the way of sizing. The properties can be further improved if the main components of sizing agents are the same to the polymer matrix [12,13].Introducing carbon nanotubes (CNTs) onto the surface of carbon fibers [14][15][16][17] is another efficient way to improve interfacial properties of CFRTP materials. Due to the outstanding mechanical properties and a large specific surface area of CNT, it can be expected to generate significantly improved mechanical characteristics for the hybrid composites as compared to the original fiber. It has been studied that CNT/carbon fiber with a large surface area could lead to better contact with the matrix, thus forming more mechanical interlocking sites [18]. Preparation of the CNT/carbon fiber hybrid fiber has been explored with several methods such as chemical vapor deposition (CVD) [19][20][21], chemical grafting [22,23], and electrophoretic deposition (EPD) [24][25][26][27][28].Since the sizing process is a standard and commercially available method of fiber surface treatment, fabrication of CNT/carbon fib...

Effect of preheat treatment on carbon fiber surface properties and fiber/PEEK interfacial behavior

“…a that no resin was adhered to the CF‐U surface. In the absence of chemical bonding between fibers and matrix, interfacial adhesion is attributed to the Van der Waal's interactions . The differential thermal shrinkage of the two materials gives rise to a pressure which increases the Vander Waal's forces at the interface.…”

An effective non‐covalent grafting approach to functionalize carbon fiber with polyethyleneimine in supercritical fluid to enhance the interfacial strength of carbon fiber/epoxy composites

“…c and f), the grooves on the fiber surface become deeper and wider, this could be caused by the etching effect of the supercritical methanol, and could increase the specific surface area. The results are consistent with previous reports, it is attributed to the excellent characteristics of high penetrability and density fluctuation of supercritical fluid . The grooves are enveloped by a layer of uniform PEI particles, more PEI is grafted onto the CF surface and the surface roughness reaches 97.6 nm.…”

Reinforcing effect of surface‐modified multiwalled carbon nanotubes on flexural response of E‐glass/epoxy isogrid‐stiffened composite panels

“…Such a finding may be due to the two main reasons: First, the fiber–matrix interfacial characteristics should be addressed. It has been well documented that the interfacial characteristics between the matrix and the reinforcement in fibrous composites play a significant role in determining their final performance . When the matrix material is reinforced by MWCNTs, the frictional slippage of fiber–matrix interface against applied load is restricted due to the presence of nanofillers.…”