The effect of simultaneous fiber surface treatment and matrix modification on mechanical properties of unidirectional ultra-high molecular weight polyethylene fiber/epoxy/nanoclay nanocomposites

Abstract

Nonpolar structure of ultra-high molecular weight polyethylene fiber leads to a weak interfacial adhesion in ultra-high molecular weight polyethylene fiber reinforced epoxy composite. Herein, synchronized fiber and matrix modifications were utilized so as to improve the interfacial adhesion, resulting in promoting mechanical properties of these composites. For this purpose, the surface of ultra-high molecular weight polyethylene fiber was chemically treated with glycidyl methacrylate and the epoxy resin was modified through incorporation of different contents of nanoclay. The mechanical properties results showed that individual modification, either fiber or matrix, can just lead to improvements around 36.74% and 10.54% in tensile strength as well as 14.28% and 4.27% in tensile modulus, respectively. However, the ultimate outcome of the study revealed that much higher improvement can be achieved in synergistic attitude. The highest enhancement around 48.31% and 26.76% in tensile strength and modulus were seen for the sample containing glycidyl methacrylate-treated ultra-high molecular weight polyethylene fibers as reinforcement and nano epoxy modified with 1 wt.% of nanoclay. Such observation could be attributed to the mechanical interlocking and chemical reaction which were arising from incorporation of nanoclay in matrix and chemical treatment of fiber surface, correspondingly. In this regard, fiber roughness and chemical bonds formed between treated fiber and modified matrix play a key role in improving interfacial adhesion. Moreover, the fractured surface of such composites studied by scanning electron microscope confirmed the mechanical results and showed that much more matrix was adhered to the fiber surface after treatment, indicating cohesive failure.

The effect of nanomodified epoxy on the tensile and flexural properties of Napier fiber reinforced composites

“…Its smooth surface with a few river‐like markings indicated the brittleness of the pristine epoxy composite, which attests to why the neat Napier/epoxy composite exhibited lower mechanical properties, compared to the other composites containing filler. This was supported by the morphological study by Mohammadalipour et al, which revealed similar images for their neat epoxy composite. The river marking zones were also observed by H. Gao and T. Qiang through SEM analysis of a virgin PLA composite using a larger magnification, confirming that the unfilled composite exhibited a brittle fracture pattern.…”

“…This suggested that, at the 5 wt% nanoclay content, the composites absorbed more work of fracture and consequently showed higher mechanical resistance. Several studies have proved that, with the addition of nanofiller to a composite, the crack propagation induced by any test was forced to follow a tortuous path . As a result, the nanocomposites showed better resistance to the applied force, describing tougher behavior, compared to the pristine one.…”

“…This weakens the interfacial interaction between them, thus degrading the mechanical properties of the developed composites. Cracks usually initiate in these preferred zones, which results in early or premature failure of the nanocomposites during the mechanical tests, thus suggesting the lower mechanical properties of the developed composites at 10 wt% clay loading. Ali et al also made a similar inference in their study.…”

Physical and Wear Properties of UHMWPE Fabric Reinforced Epoxy Composites

“…Major constituents of fibre reinforced polymer (FRP) composites are matrix and reinforcement. Thermosetting or thermoplastic resins used as matrix material [5], and synthetic or natural fibre/fabric is used as reinforcements [9][10][11]. Epoxy is the most widely used thermoset matrix and most of the industries use epoxy for fabrication of composites due to their qualities like low processing temperature, thermal stability, adhesion, and hold good mechanical properties [4].…”

“…Epoxy is the most widely used thermoset matrix and most of the industries use epoxy for fabrication of composites due to their qualities like low processing temperature, thermal stability, adhesion, and hold good mechanical properties [4]. After conventional synthetic fibres like Glass fibre, Kevlar fibre, and Carbon fibre; UHMWPE fibres are most widely used as reinforcement in the recent days [5][6][7][8] because-of distinguished physical and mechanical properties UHMWPE fibres considered as third generation synthetic fibres [5][6][7][8].…”