Sustainable Multifunctional Graphene Oxide‐Coated Jute/Epoxy Composite Interlayers for Fatigue‐Resistant and Self‐Healing Aluminium Adhesive Joints

ABSTRACT

Adhesively bonded aluminium joints are widely used in lightweight structures, but their durability is often limited by interfacial crack growth, fatigue damage, moisture ingress, and limited recovery of fracture resistance after damage. This study develops a sustainable, multifunctional jute/epoxy composite interlayer by combining graphene oxide‐coated jute fabric with a dual epoxy–mercaptan microcapsule self‐healing chemistry to achieve fatigue‐resistant aluminium adhesive joints. EN AW‐6061‐T6 adherends were bonded using neat epoxy, graphene nanoplatelet‐modified epoxy, alkali‐treated fiber interlayers, and graphene oxide‐coated self‐healing jute/epoxy interlayers. The joints were evaluated by lap‐shear testing, Mode I DCB fracture testing, fatigue crack growth analysis, water absorption, hygrothermal aging, healing efficiency assessment, and fracture surface microscopy. The optimum 1.00 wt% graphene oxide‐coated jute system achieved a lap‐shear strength of 24.0 MPa and a Mode I propagation fracture energy of 1760 J m ⁻² . Under cyclic Mode I loading, crack growth was restricted to 77 mm after 300,000 cycles, compared with 112 mm for the neat epoxy joint. Healing efficiency increased from nearly 64% after 6 h to 91% after 48 h. The improved performance is attributed to fiber bridging, crack deflection, interfacial anchoring, resin ligament formation, and microcapsule‐assisted crack‐plane repair.