Electrolytic Surface Treatment for Improved Adhesion between Carbon Fibre and Polycarbonate

Abstract

To achieve good mechanical properties of carbon fibre-reinforced polycarbonate composites, the fibre-matrix adhesion must be dialled to an optimum level. The electrolytic surface treatment of carbon fibres during their production is one of the possible means of adapting the surface characteristics of the fibres. The production of a range of tailored fibres with varying surface treatments (adjusting the current, potential, and conductivity) was followed by contact angle, inverse gas chromatography and X-ray photoelectron spectroscopy measurements, which revealed a significant increase in polarity and hydroxyl, carboxyl, and nitrile groups on the fibre surface. Accordingly, an increase in the fibre-matrix interaction indicated by a higher interfacial shear strength was observed with the single fibre pull-out force-displacement curves. The statistical analysis identified the correlation between the process settings, fibre surface characteristics, and the performance of the fibres during single fibre pull-out testing.

Experimental investigation of electrolytically treated and silane grafted carbon fiber-reinforced thermoplastic polyurethane composites

“…Clearly, the increase in the load capacity of the oxidized fiber composites is not significant due to the fact that electrolytic oxidation treatment of CF doesn't really enhance the properties of the composite samples but they create active sites on the surface of the Carbon which reduces the difference in polarity, roughens the surface and can adhere and interact well with the TPU matrix. 25 The drop in the tensile properties at higher electrolytic treatment concentration could be due the fact that upon electrolytic oxidation treatment on carbon fibers, the fiber's outer layer gets removed and the surface becomes rougher and has more active spots. However, with higher concentrations of the treatment, more layers could be irregularly removed as a result of irregular oxidation corrosion caused by the electric current densities of CFs surfaces inside or outside the bundle making the fiber weak.…”

“…Gulyas et al 24 performed electrochemical oxidation treatment on Polyacrylonitrile (PAN) based carbon fibers by varying the concentrations of electrolytes from 2 to 20 wt.% and voltage from 0.5 to 5 V. The results claimed a close relationship between the surface chemistry and the interlaminar shear strength of the modified fiber-reinforced composites. Kamps et al 25 also studied electrolytically treating the carbon fibers, which were later reinforced into polycarbonate matrix. The surface treatment parameters such as voltage, current, and conductivity were varied and analyzed in detail to observe the effect on the performance of Carbon fiber-reinforced composites.…”

Effect of Fiber Sizing Levels on the Mechanical Properties of Carbon Fiber-Reinforced Thermoset Composites

“…The interfacial adhesion between the fiber and matrix is paramount importance to designing and producing the intended fiber application for high-performing functional composite. Several techniques exist to accomplish this, including surface treatment and sizing the reinforcing fibers while the product is being manufactured [ 20 , 21 , 22 , 23 ]. The process phase when a thin film of organic polymer is placed onto the fiber surface is known as the “sizing” of carbon fibers.…”

“…Surface engineering is therefore highly required to achieve the optimum adhesion level. Researchers have looked at how carbon fiber surface treatment and size affect the interfacial characteristics of various polymeric matrices [ 20 , 21 , 22 , 23 , 28 ]. Kamps et al [ 21 ] investigated the impact of electrolytic surface treatment parameters, such as current, voltage, and conductivity, on the adhesion characteristics of carbon fiber-reinforced polycarbonate composites.…”

Caracterização da etapa de estabilização do processo produtivo de fibra de carbono a partir de poliacrilonitrila utilizando algoritmos inteligentes

“…Conforme esquematizado na eletrólise deste processo, a fibra de carbono atua como anodo, cedendo elétrons para as placas de grafite presentes na solução aquosa, o que é denominado como catodo. Assim, visando manter o equilíbrio eletrolítico, a fibra atrai os elétrons da solução, adicionando, dessa forma, grupos funcionais em sua estrutura, sendo estes compostos, principalmente, de oxigênio (Kamps et al, 2018).…”