Iron-based reversible adhesives: Effect of particles size on mechanical properties

Abstract

A hot melt adhesive -mainly used for bonding plastic component in automotive field -was modified with different ironbased particles to give it a reversible behaviour. Mechanical and physical properties of these reversible adhesives were experimentally assessed in the work. The modified adhesives, coupled with electromagnetic induction, are able to guarantee separation of the joints without any damage to the substrates for recycling, reuse or repairing of components. Single lap joint specimens were prepared using epoxy/glass fibres substrates and tests were carried out on neat and modified adhesive with 5% weight of iron and iron oxide. Three different Fe particles size were tested: 450 mm, 60 mm and 1-6 mm. The particles size of iron oxide was 50 nm. Separation was studied using single lap joint specimens under electro-magnetic induction. Experimental results showed that the maximum peak load decreases when the average particles sizes increase. The peak loads of the smallest particles were equal to the ones of the pristine adhesive. The elongation of the adhesives increases when the adhesive is modified with both iron and iron oxide particles. Finally, experimental tests on single lap joints coupled with electro-magnetic induction showed that separation of the substrates is possible using iron oxide particles. Electro-magnetic tests conducted on particles alone, helped to understand that bigger particles are able to overcome the melting temperature of the adhesive but hot-melt adhesives modified with these particles are not able to reach the melting. These tests showed that the number of particles into the adhesive matrix is very important for this kind of tests.

Effect of graphene nanoplatelets on the impact response of a carbon fibre reinforced composite

“…In order to obtain the best resolution, secondary electron emission signals were used with an accelerating voltage of 1.4 kV. The specimens were properly coated with gold to have better images [29]. The results of the Scanning Electron Microscope (SEM) are discussed in Section 3.3.…”

Review on Adhesives and Surface Treatments for Structural Applications: Recent Developments on Sustainability and Implementation for Metal and Composite Substrates

“…The heating happens very fast and melts or decomposes the adhesive material near the primer layer or the primer layer itself. This process causes a loss in strength so that the bonded joint can be easily debonded [ 179 , 193 , 194 , 195 ].…”

The Mechanical Performance of Re-Bonded and Healed Adhesive Joints Activable through Induction Heating Systems

“…Lu et al [ 5 ] and Banea et al [ 6 ] reported the newest patented and proposed in literature technologies able to ease the separation processes of adhesive joints. These new and innovative technologies have been studied because the current traditional techniques (the use of chemical agents, heat, or mechanical cut) lead to damage to substrates or components [ 5 , 6 , 7 ]. Among the techniques presented in [ 5 , 6 ], some of them can be fully reversible since they use thermoplastic adhesives that can be remelted (as compared to thermoset adhesives) and thus they can be used for repair, overhaul or avoid waste during the bonding operations.…”

“…For these reasons, the need to find alternative techniques is crucial to promote the rapid separation of adhesively bonded components. Many studies [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ] have been presented in the literature regarding the dismantling of the adhesive joints of thermoplastic components. The use of iron oxide nanoparticles dispersed in a holt-melt adhesive that is activable through induction heating has been extensively studied by Ciardiello et al [ 7 , 8 , 9 , 10 ].…”

“…Many studies [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ] have been presented in the literature regarding the dismantling of the adhesive joints of thermoplastic components. The use of iron oxide nanoparticles dispersed in a holt-melt adhesive that is activable through induction heating has been extensively studied by Ciardiello et al [ 7 , 8 , 9 , 10 ]. These research activities [ 7 , 8 , 9 , 10 ] showed that the separation of adhesively bonded joints is feasible by adopting weight concentrations from 3% wt.…”