Modified Silane Polymer Adhesive: Effect of Aluminum Substrate Treatment Methods and the Adhesive Thickness on Adhesive Durability and Joint Strength

Document Type : Research Paper

Authors

Department of Adhesive and Resin, Faculty of Petrochemical, Iran Polymer and Petrochemical Institute, P.O. Box 14975-112, Tehran, Iran

Abstract

Hypothesis: Adhesives and sealants based on modified silane polymer (MS polymer) are increasingly gaining market share in adhesive and sealant market place due to their desirable performance in various applications.
Methods: In order to find the most optimal adhesive processing parameters, different stages of aluminum surface treatment in three stages were investigated, including the surface degreasing, sanding and priming. In this manner, the performance of four different types of degreasing agents and two kinds of silane-based primers were investigated individually. The optimum bond line thickness was also determined through adhesive joint shear strength. The effect of different degreasing agents and silane-based primers were evaluated through lap-shear strength. The effect of adhesive layer thickness was studied through lap-shear strength and cleavage strength tests.
Findings: Optimum bond line thickness was determined at 0.5 mm based on the results of the adhesive shear strength, whereas the results of the fracture toughness indicated 1.25 mm as the optimum adhesive layer thickness. The lower adhesive strength in thicker bond lines may well be due to the possible formation of air traps and lower constrained effect of the substrate. Therefore, the least requirements for aluminum surface treatment was surface degreasing followed by sanding which results in a transition from adhesive fracture mode to cohesive fracture. The use of two kinds of silane-based primers containing the amine group, triethoxy silylpropylamine (APS) and the other with epoxy group, glycidoxypropyl trimethoxysilane (GPS) was more efficient in improving joint durability even after 2500 h cyclic aging with the more pronounced results for the APS.

Keywords

References

  1. Petrie E.M., MS Polymers in Hybrid Sealants, accesed 25/1/2020
  2. Ebnesajjad S., Handbook of Adhesives and Surface Preparation: Technology, Applications and Manufacturing, William Andrew, 2010.
  3. Petrie E.M., Theories of Adhesion, Handbook Adhesive and Sealants, 2nd ed., McGraw-Hill, New York, Chapt. 2, 2006.
  4. Ebnesajjad S. and Ebnesajjad C., Surface Treatment of Materials for Adhesive Bonding, William Andrew, 2013.
  5. Boutar Y., Naïmi S., Mezlini S., and Ali M.B.S., Effect of Surface Treatment on the Shear Strength of Aluminium Adhesive Single-Lap Joints for Automotive Applications, Int. J. Adhes. Adhes., 67, 38-43, 2016.
  6. Critchlow G.W. and Brewis D.M., Review of Surface Pretreatments for Aluminium Alloys, Int. J. Adhes. Adhes., 16, 255-275, 1996.
  7. Broughton W.J. and Mera R.D., Review of Durability Test Methods and Standards for Assessing Long Term Performance of Adhesive Joints, National Physical Laboratory, 1997.
  8. Costa M. Viana G., Da Silva L.F.M., and Campilho R., Environmental Effect on the Fatigue Degradation of Adhesive Joints: A Review, J. Adhes., 93, 127-146, 2017.
  9. Harris A.J., Vaughan B., Yeomans J.A., Smith P.A., and Burnage S.T., Surface Preparation of Alumina for Improved Adhesive Bond Strength in Armor Applications, Ceram Eng. Sci. Proc., 33, 149-160, 2012.
  10. Banea M.D., da Silva L.F.M., and Campilho R.D.S.G., The Effect of Adhesive Thickness on the Mechanical Behavior of a Structural Polyurethane Adhesive, J. Adhes., 91, 331-346, 2015.
  11. Cognard J.Y., Créac’hcadec R., Sohier L., and Davies P., Analysis of the Nonlinear Behavior of Adhesives in Bonded Assemblies-Comparison of TAST and Arcan Tests, Int. J. Adhes. Adhes., , 28, 393-404, 2008.
  12. Davies P., Sohier L., Cognard J.-Y., Bourmaud A., Choqueuse D., and Rinnert E., Influence of Adhesive Bond line Thickness on Joint Strength, Int. J. Adhes. Adhes., 29, 724-736, 2009.
  13. Kinloch A.J., Korenberg C.F., and Tan K.T., Durability of Structural Adhesive Joints, Appl. Sci., New York, 1983.
  14. Leena K., Athira K.K., Bhuvaneswari S., Suraj S., and Rao V.L., Effect of Surface Pre-treatment on Surface Characteristics and Adhesive Bond Strength of Aluminium Alloy, Int. J. Adhes. Adhes., 70, 265-270, 2016.
  15. Hamdi M., Saleh M.N., and Poulis J.A., Improving the Adhesion Strength of Polymers: Effect of Surface Treatments, J. Adhes. Sci. Technol., 34, 1853-1870, 2020.
  16. Mohseni M., Mirabedini M., and Shamardani K., Adhesion Improvement of Epoxy Coating on Aluminium Sub- Strate Using an Amino-Silane Compound, Iran. J. Polym. Sci. Technol. (Persian), 2, 103-110, 2003.
  17. Nakamae K., Yamaguchi K., Asaoka S., and Karube Y., Lifetime Expectancy of Polyurethane Binder as Magnetic Recording Media, Int. J. Adhes. Adhes., 16, 277-283, 1996.
  18. Digby R.P. and Shaw S.J., The international Collaborative Programme on Organosilane Coupling Agents: An Introduction, Int J. Adhes. Adhes., 18, 261-264, 1998.
Iranian Journal of Polymer Science and Technology
Volume 34, Issue 1 - Serial Number 171
May and June 2021
Pages 43-54

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