Exposure of structural epoxy adhesive to combination of tensile stress and γ-radiation. (March 2020)

• Record Type: Journal Article
• Authors: Zimmermann, J.; Sadeghi, M.Z.; Schroeder, K.U.
• Is Part Of: International journal of adhesion & adhesives. Volume 97(2020)
• Publication Date: 2020-03
• Subjects: Epoxides (A) -- Mechanical properties of adhesives (D) -- Environmental issues (D) -- Infrared spectroscopy (C) -- γ-Radiation -- Space application; Adhesion -- Periodicals; Adhesives -- Periodicals; Adhésion (Physique) -- Périodiques; Adhésifs -- Périodiques; Adhesie; Kleefstoffen; Adhesion; Adhesives; Periodicals; 668.3
• DOI: 10.1016/j.ijadhadh.2019.102496
• Languages: English
• ISSNs: 0143-7496

Abstract

Abstract: Mass is money! This sentence applies even more in space transportation than in aviation, due to the enormous cost it takes to carry payload in orbit. With the development of high temperature adhesives and the rise of composite materials like CFRP, adhesive bonding has experienced enormous growth in the space sector. Opposing to terrestrial application, the adhesive joint has to withstand unique environmental conditions. Adhesive systems belong to the group of polymers. Thus, the effect of radiation, especially ionizing radiation, has an enormous influence on the structural integrity of adhesive systems. In a space exploration mission e.g. on the lunar surface, the adhesive has to withstand mechanical loads in combination with radiation environment. This paper investigates the combined effect of tensile stress and γ-radiation on the mechanical properties of a 2-component epoxy adhesive. It's a matter of the greatest importance to investigate the possible degradation of the adhesive in combination with irradiation and tensile loading due to increased chain scission of stressed molecules. For structural adhesives, such phenomena are not covered well in the literature. In the present work, bulk specimens of the investigated adhesive are milled out from a plate and exposed to a 60 Co source. During the irradiation they were loaded in tensile direction. Afterwards, the specimens were inspected by FTIR spectroscopy and then tested destructively in order to determine the potentially degraded mechanical properties. The results show that the mechanical properties of the bulk adhesive stay constant for non-irradiated, irradiated non-loaded and irradiated loaded specimen which concludes that the investigated adhesive is not weakened by the combination of γ-radiation (32.4 kGy) and tensile loading.