Effects of particle size and distribution of the sizing agent on carbon fiber/epoxy composites interfacial adhesion

Abstract

This article aims to study the effects of particle size and distribution (PSD) of sizing agent on surface physical and chemical properties of the carbon fiber. Five kinds of sizing agents with various PSD named P‐1 to P‐5 sizing were applied in order to investigate the influences on interfacial properties between the carbon fiber and the matrix. The surface characteristics of carbon fibers were investigated to determine morphology, chemical composition, surface energy, interfacial thickness, and interlaminar shear strength (ILSS). The results revealed that, as the particle size decreasing, the O1s/C1s composition ratios, surface energy and the interfacial thickness show a growing trend whereas the surface roughness reduces mildly. Similarly, the ILSS of the carbon fiber/epoxy composites have also increased by more than 8% with the decreased particle size. This demonstrates that small particle size with multimodal PSD in sizing is advantageous for effective wetting and force transition in the interfacial adhesion. Actually, when the mean particle size is around 110 nm (P‐3 sizing), the emulsion droplets can repair the surface irregularity and hold back excessive stress most remarkably, leading to optimal contributions to the improvement of ILSS. Based on these results, a mechanism concerning particle arrangement in sizing and interfacial strengthening in carbon fiber/epoxy composites was proposed, which provided a reasonable explanation to analyze the effects of PSD in sizing and interfacial bonding. POLYM. COMPOS., 39:E2036–E2045, 2018. © 2017 Society of Plastics Engineers

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

“…In contrast, the IFSS of CF‐370°C /PEEK increased from 40.16 MPa to 46.32 MPa by 15.34%, which was not consistent with the activated carbon atoms. For thermoset matrix like epoxy resin, the increase of the concentration of the activated carbon atoms meant the improvement of surface chemical activity, which was beneficial to the interfacial adhesion . However, for PEEK matrix in this work, the interfacial adhesion showed different tendency compared with that of thermoset composites.…”

Effects of fatty acid modified epoxy resin on long‐chain epoxy and its physical properties

“…This is due to the interfacial instability in CFRP compositions. Thus, additional research is required 35,36 …”

Effects of polyetherimide sizing involving carbon nanotubes on interfacial performance of carbon fiber/polyetheretherketone composites

“…The data about average diameter of PEI particles were listed in Table 1. As presented in the table, the particle size of majority samples is distributed in the range of 100–300 nm, which is believed as an appropriate scope for CF sizing 33 . Nevertheless, it is worth noting that those single numerical values could not reflect the size distribution totally, and the distribution curve of the emulsion should be concerned.…”