Layer-by-Layer Self-Assembly Strategy for Surface Modification of Aramid Fibers to Enhance Interfacial Adhesion to Epoxy Resin.

Muhuo Yu,Baihua Liu,Haijuan Kong,Cuiqing Teng,Minglin Qin,Zhaomin Li

doi:10.3390/polym10080820

Muhuo Yu, Baihua Liu + Show 4 more

Open Access

https://doi.org/10.3390/polym10080820

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Abstract

In this work, the layer-by-layer self-assembly technology was used to modify aramid fibers (AFs) to improve the interfacial adhesion to epoxy matrix. By virtue of the facile layer-by-layer self-assembly technique, poly(l-3,4-Dihydroxyphenylalanine) (l-PDOPA) was successfully coated on the surface of AFs, leading to the formation of AFs with controllable layers (nL-AF). Then, a hydroxyl functionalized silane coupling agent (KH550) was grafted on the surface of l-PDOPA coated AFs. The properties such as microstructure and surface morphology of AFs before and after modification were characterized by FTIR, XPS and FE-SEM. The results confirmed that l-PDOPA and KH550 were successfully introduced into the surface of AFs by electrostatic adsorption. The interfacial properties of AFs reinforced epoxy resin composites before and after coating were characterized by interfacial shear strength (IFSS), interlaminar shear strength (ILSS) and FE-SEM, and the results show that the interfacial adhesion properties of the modified fiber/epoxy resin composites were greatly improved.

Highlights

Owing to their unique characteristics such as high strength, high modulus, low density and high resistance, aramid fibers has become one of the ideal reinforcements for various high-performance composites in the fields such as aerospace, sports, automobiles and aviation [1,2,3,4,5,6]
The interfacial adhesion of aramid fiber to epoxy matrix was successfully improved via the layer-by-layer self-assembly method
The chemical structure, composition, micro-morphology and roughness of the aramid fiber surface before and after modification were characterized by FTIR, XPS, XRD, TGA and FE-scanning electron microscopy (SEM)

Summary

Introduction

Owing to their unique characteristics such as high strength, high modulus, low density and high resistance, aramid fibers has become one of the ideal reinforcements for various high-performance composites in the fields such as aerospace, sports, automobiles and aviation [1,2,3,4,5,6]. A variety of surface modification methods, such as chemical etching and grafting [7,8,9,10], ultrasonic [11], γ-ray radiation [12], plasma treatment [13,14,15,16,17] and polymer coating [18], have been developed to improve the interfacial adhesion to resin matrix. These approaches involve stringent reaction conditions and high cost instrument, and may even cause environmental pollution. It is necessary to develop a low-cost and environmental-friendly method without damage to mechanical properties for surface modification of aramid fibers

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Results

Conclusion