The goal of this research was to develop an appliqué system to protect an aluminum surface previously coated with a RTV silicone rubber. The appliqué consisted of a poly (urethane) - based film coated with a suitable adhesive. Two adhesion problems were studied in this project: 1) adhesion to the contaminated aluminum surface, and 2) adhesion to the protective film of the appliqué. Adhesion can occur according to several mechanisms: physical adsorption, chemical bonding, diffusion, electrostatic forces, and mechanical interlocking. According to the type of surfaces involved in a particular adhesion problem, one of several of these mechanisms are implicated in the adhesion process. Adhesion can also be described by thermodynamics. To obtain high adhesion, the adhesive should easily wet the adherent surface to maximize the contact surface between the two materials. Knowing the surface energies of the adhesive and adherent, it is possible to predict whether the adhesion will be thermodynamically favored. The surface properties of the aluminium are modified by the traces of RTV left after its removal. Surface characterization by scanning electron microscopy (SEM) was used to compare the chemistry and roughness of the aluminum surfaces before RTV application and after its removal. Profilometry was employed to determine the roughness of the metallic surfaces. The surface energies of the different materials involved in the project have been calculated using contact angle measurement data. Several commercial adhesives have been tested using a 180" peeling test. The adhesives studied include hot-melt, pressure-sensitive, and liquid adhesives, and possess a variety of chemistries, including: Ethylene Vinyl Acetate (EVA), cyanoacrylate, acrylic, rubber, and silicone. The results of these mechanical tests show that the acrylic-based pressure-sensitive adhesives are the most suitable for this particular project. Moreover, the application of pressure-sensitive adhesives to the substrate is easier than for the other types of adhesives. Two acrylic-based pressure-sensitive adhesives met the project requirements: 1) adhesive 8314 from Adhesive Research, Inc., and 2) adhesive 9495 MPF from 3M.
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Details
Title
Adhesion of protective coating appliques on contaminated aluminum surfaces
Creators
Gwénaëlle Proust - DU
Contributors
Thomas Twardowski (Advisor) - Drexel University (1970-)
Awarding Institution
Drexel University
Degree Awarded
Master of Science (M.S.)
Publisher
Drexel University; Philadelphia, Pennsylvania
Resource Type
Thesis
Language
English
Academic Unit
Materials (Science and) Engineering (Metallurgical Engineering) [Historical]; College of Engineering (1970-2026); Drexel University