Exploring the tensile strain energy absorption of hybrid modified epoxies containing soft particles

In this paper, tensile strain energy absorption of two different hybrid modified epoxies has been systematically investigated. In one system, epoxy has been modified by amine-terminated butadiene acrylonitrile (ATBN) and hollow glass spheres as fine and coarse modifiers, respectively. The other hybrid epoxy has been modified by the combination of ATBN and recycled Tire particles. The results of fracture toughness measurement of blends revealed synergistic toughening for both hybrid systems in some formulations. However, no evidence of synergism is observed in tensile test of hybrid samples. Scanning electron microscope (SEM), transmission optical microscope (TOM) and finite element (FEM) simulation were utilized to study deformation mechanisms of hybrid systems in tensile test. It is found that coarse particles induce stress concentration in hybrid samples. This produces non-uniform strain localized regions which lead to fracture of hybrid samples at lower tensile loading and energy absorption levels.

Research highlights
► Two epoxy systems have been modified by combination of fine and coarse modifiers.
► While both hybrid systems reveal synergistic KIC, no synergism is observed in tensile test.
► It is found that coarse particles induce stress concentration in hybrid samples.
► Stress concentration leads to fracture of samples at lower energy absorption levels.