Single-Lap Joints Bonded with Epoxy Nanocomposite Adhesives: Effect of Organoclay Reinforcement on Adhesion and Fatigue Behaviors

Abstract

Organoclay, such as organo-modified montmorillonite (MMT), is one of the potential filler candidates in the preparation of epoxy nanocomposite adhesives for automotive and civil engineering industries. However, there is no systematic research on the effect of organoclay reinforcement on its adhesion and fatigue behaviors in shear loading. Here, single-lap joints (SLJs) of stainless steel substrates bonded with epoxy/MMT nanocomposite adhesives, consisting of diglycidyl ether of bisphenol A and poly(oxypropylene) diamine with various weight contents of a commercialized MMT filler, were prepared. The dispersity of MMT and bulk mechanical properties were investigated by wide-angle X-ray scattering/ diffraction, the uniaxial tensile test, and dynamic mechanical analysis. The lap shear strengths and failure modes were investigated based on the single-lap shear test, and the joint durability was examined by using the fatigue test with various shear stress levels. Through the incorporation of the MMT fillers in epoxy resins, the lap shear strengths increased from 25 to 40 MPa, the failure modes changed from adhesive failure mode to cohesive one, and the fatigue lifetimes prolonged with the addition of a small amount of MMT.

Adhesion Promoting Copolymer of Acetate-Protected Vinyl Catechol with Glycidyl Methacrylate: Unraveling Deprotection, Adsorption, and Adhesion Behaviors on Metal Substrates

“…The PGMA- co -PVCa-coated metal substrates, including SUS304, A7075, and duralumin substrates, were used as adherends for the preparation of adhesive-bonded SLJs. The detailed preparation procedure of the SLJs is described in our previous work . Briefly, the as-prepared epoxy adhesive precursor was first coated on the edge surfaces of two PGMA- co -PVCa-modified adherends and sandwiched between two adherends with an overlapping area of ∼5 × 5 mm 2 .…”

“…The detailed preparation procedure of the SLJs is described in our previous work. 42 Briefly, the as-prepared epoxy adhesive precursor was first coated on the edge surfaces of two PGMA-co-PVCa-modified adherends and sandwiched between two adherends with an overlapping area of ∼5 × 5 mm 2 . The thicknesses of the overlapping adhesives for all of the joints were controlled to be ∼0.2 mm using appropriate spacer thicknesses.…”

Deformation Behavior of Polyurethane Adhesive in the Single-Lap Joint Based on the Microbeam X-ray Scattering Method

“…The resultant PU is thermoplastic as shown in Figure S2. The method of adjusting adhesive thickness and fixing of sample was the same as those used in our previous study . The size of the sheet samples used for uniaxial test was 30 mm × 3 mm × 1 mm.…”

“…To produce adhesives with high strength and durability, the multi-scale structure must be clarified from the molecular to macroscopic scale of the adhesive. Currently, epoxy, polyurethane (PU), and acrylic resins are the mainly used adhesives in commercial products, and research on their bulk and adhesive properties has been extensively carried out in recent years to improve the bonding performance. − …”

Imidazole substituted benzothiadiazole derivatives as latent curing agent for epoxy thermosetting resin

“…Epoxy resin (EP), as an important resin matrix, has been widely used in coatings, 1,2 electrical insulation, 3,4 adhesives 5–7 and composites 8–10 industries for its good mechanical properties, corrosion resistance and chemical resistance, excellent electrical properties, low shrinkage and excellent bonding properties 11–13 . Vacuum assisted resin transfer molding (VARTM) is widely used to manufacture large and EP‐based composite materials with low cost and high efficiency 14–17 .…”