Chemical superficial treatments in Al2024 for improve the adhesion on polypropylene

Abstract

The joint of materials employing adhesives has been used for a long time. However, the possibility of generating joints between materials with remarkably dissimilar surface free energies, as in the case of joining metals and polymeric materials (with hydrophobic nature), is the main goal of this work and a novel area of investigation. In this work, a broad range of different compounds to prepare surfaces of Al2024 and polypropylene (PP) has been studied, in order to be joined subsequently by two kinds of adhesives: structural two-component adhesive DP8005 and double-sided adhesive tape RP45 (due to its interest in fast assembling operations). Surface treatments used in this work are based on non-silane compounds, in particular, two agents of maleinization (in solution), a nitrant agent at different concentrations, due to its behaviour depends on if it reacts as strong acid, oxidant agent or nitrant agent, following by a microwave treatment; a phosphating process; a glycidyl methacrylate treatment and, by a way of comparison, a conventional priming agent. The silane treatments are reported in other work (1).

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