Enhancement of interface performance between shape memory alloy fiber and polymer matrix using silane coupling agent KH550 and Al₂O₃ nanoparticles

The interface performance of nickel-titanium (Ni-Ti) shape memory alloy (SMA) fiber reinforced vinyl ester resin composites was investigated in this work. All the SMA fibers were pre-treated with H₂SO₄ and NaOH solution. The fiber surfaces were coated with Al₂O₃ nanoparticles and silane coupling agent KH550. For comparison, two groups of SMA fibers were coated only with the silane coupling agent or the nanoparticles. Furthermore, the effect of the nanoparticle content on the interface performance of the composites was investigated for Al₂O₃ nanoparticle contents ranging from 1 wt% to 4 wt%. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to study the effect of the surface modifications. The results demonstrate that all the modified methods enhance the interface strength of the SMA/vinyl ester resin, but samples with SMA fibers coated with both the silane coupling agent and 3 wt% Al₂O₃ nanoparticles have the best interface performance. SEM observations show that the dispersion of nanoparticles increases when the silane coupling agent is added to the composites. POLYM. COMPOS., 39:3040–3047, 2018.