Influence of Water Absorption and Temperature on the Mechanical Properties of Discontinuous Carbon Fiber Reinforced Polyamide 6

Carbon fiber reinforced thermoplastics (CFRTPs) are expected to be used for the structural parts of automobiles and aircraft due to their mechanical properties, such as high specific stiffness, high specific strength, short molding times and high recyclability. The fiber/matrix interface of the composite plays an important role in transmitting stress from the matrix to the reinforcing fibers. It was reported that grafting of carbon nanotubes (CNTs) on the carbon fiber can improve the fiber/matrix interfacial property. We have reported that CNTs, which are directly grafted onto carbon fiber using Ni as the catalyst by the chemical vapor deposition (CVD) method, can improve the fiber/matrix interfacial shear strength (IFSS) of carbon fiber/polyamide 6 (PA6). For practical use of CFRTPs, it is important to clarify the effects of water absorption on the mechanical properties of the composite material. In this study, the effects of water absorption on the fiber–matrix interfacial shear strength (IFSS) of carbon fiber reinforced polyamide resin and CNT-grafted carbon fiber reinforced polyamide resin were clarified by the single fiber pull-out test for specimens preserved in air, then in water for 24 h and re-dried after water absorption. The IFSS of carbon fiber/PA6 was significantly decreased by water absorption. In contrast, CNT-grafted carbon fiber/PA6 showed smaller degradation of the IFSS by water absorption.

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Evaluation of mechanical properties and EMI shielding effectiveness of long carbon fiber reinforced thermoplastic with different matrix

Journal of Composite Materials ◽

10.1177/0021998320959752 ◽

2020 ◽

pp. 002199832095975

Author(s):

Jeong U Roh ◽

Dong Jun Kwon ◽

Joong Seob Guk ◽

Jin Gon Kim ◽

Hyun Young Lee ◽

...

Keyword(s):

Mechanical Properties ◽

Carbon Fiber ◽

Electromagnetic Interference ◽

Polyamide 6 ◽

Work Of Adhesion ◽

Fiber Reinforced ◽

Shielding Effectiveness ◽

Carbon Fiber Reinforced ◽

The Difference ◽

Long Carbon Fiber

In the present study, the difference of long carbon fiber reinforced thermoplastic (C-LFT) depending on the type of polymer resins at the same carbon fiber content (30 wt.%) was compared. The different types of C-LFT were made using five polymer resins such as polyamide 6, polyamide 6,6, polycarbonate, high density polyethylene and polypropylene. Tensile test, flexural test, and unnotched Izod impact test were carried out and the cause of difference in the mechanical properties was considered by analyzing the adhesion characteristics. Fracture appearance and work of adhesion between the fiber and the resin were observed. In addition, the difference and its cause in electromagnetic interference shielding effectiveness (EMI SE) was investigated. From the results, the polyamide 6 is most appropriate to the carbon fiber among the samples in the aspects of interfacial shear strength and fiber dispersion.

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