High crosslink density and nano-ano enhancement: Performance of bisphenol A epoxy resin adhesives in corrosive environment

Traditional inkjet printheads typically utilize adhesives to combine electronic components with piezoelectric materials. When immersed in ink for extended periods, the interface often experiences debonding. To address this issue, we developed an epoxy resin adhesive by using bisphenol A epoxy resin and curing agent DDM, and simultaneously incorporating nano-SiO₂ as a filler. Through non-isothermal kinetics, we optimized the curing temperature and determined its activation energy to be 52.8 kJ mol⁻¹, fitting the SB (m, n) model. The highly crosslinked network it forms can effectively resist the intrusion of water and solvents. Results indicate that 2.0 wt% nano-SiO₂ is optimal, reducing liquid absorption rates in ethylene glycol ether and water by 78 % and 17.2 %, respectively, over 180 days. DMA and XPS tests show that nano-SiO₂ increases the crosslinking density and mechanical stability, resulting in higher storage modulus and glass transition temperature. An addition of 2.0 wt% provided the highest strength before and after aging. FTIR spectra before and after aging indicate that the adhesive did not undergo hydrolysis, and the addition of nano-SiO₂ reduces the absorption rates of solvents and water. Our research offers valuable insights for developing high-performance adhesives suitable for corrosive environments, such as inkjet printheads.