The effect of modified tannic acid (TA) eco-epoxy adhesives on mode I fracture toughness of bonded joints

Mohamed Saleh, Nataša Z. Tomić, Aleksandar Marinković, Sofia Teixeira de Freitas
January 2021
Cite DOI

Abstract

Two synthesized eco-epoxy components based on TA: (A) glycidyl ether and (B) glycidyl phosphate ester, are used, as a replacement for the Bisphenol A (BPA) based epoxy component, for bonding aluminum (Al) and carbon fiber reinforced polymer (CFRP). Their effect on the mode I fracture toughness (GI) is evaluated by Double Cantilever Beam (DCB) testing while using Digital Image Correlation (DIC) for in-situ crack tip monitoring. Compared to the reference adhesive, an improvement of (GI) of Al (43%) and CFRP (100%) is obtained when using adhesive B. Moreover, regardless of the adherend material, a stick-slip pattern of crack growth is observed. Weak adhesion of the reference adhesive leads to an adhesive failure vs. a cohesive-adhesive failure in the case of adhesive B. On the contrary, the modification of adhesive A has an adverse effect on the GI of Al (−33%) and CFRP (−78%) as opposed to their reference counterparts.

Type
Journal article
Publication
Polymer Testing
Adhesive Digital Image Correlation (DIC) Double Cantilever Beam (DCB) Eco-Epoxy Mode I Fracture Toughness
Mohamed Saleh
Postdoc Researcher

My research interests in fracture mechanisms of bi-material bonded joints with thick bondlines.

Sofia Teixeira de Freitas
Sofia Teixeira de Freitas
Principal Investigator

Sofia Teixeira de Freitas researches the structural integrity of bonded and layered materials to enable durable, sustainable structures. She is also an accredited group facilitator, committed to building academic environments grounded in cooperation and inclusion—key to overcoming technological limits and addressing the challenges of a truly sustainable society.