Advancing the 3D printing of magnetoactive epoxy shape memory composites: correlating the rheology, printability, and shape fidelity

• DOI: 10.1007/s10965-024-04247-2
• Publication Date: 2025-01-18T05:22:00Z
• Authors: Mohammad Hossein ...; Zoubeida Ounaies
• Keywords: Shape-memory polymer

Abstract shape memory polymers (SMPs) stand out as versatile candidates possessing actuation, shape memory effect, and sensing capabilities. This study investigates the impact of iron oxide (Fe3O4) functionalization by Polyethylene Glycol (PEG) on the magnetic and rheological properties of SMP composites. Optical microscopy shows improved Fe3O4 particle dispersion and distribution due to PEG coating. Magnetic characterization using Vibrating Sample Magnetometry (VSM) reveals enhanced mass magnetization of the functionalized Fe3O4-loaded SMP composites. By replacing unfunctionalized Fe3O4 with Fe3O4_PEG20, the saturation magnetization of SMP composites improved by 19%. Rheological tests reveal that fumed silica has a major effect on the shear thinning behavior of SMP dispersions. Also, PEG functionalized dispersions exhibit enhanced shear thinning behavior and shape fidelity compared to unfunctionalized dispersions. Shape fidelity test revealed the reduction of die-swell of SMP dispersions loaded with Fe3O4_PEG30 and improved percent deformation from 439–5% for SMP(93.39)_Silica(4.11)_Fe3O4(2.5) and SMP(83.81)_Silica(3.69)_Fe3O4(12.5)_PEG30, respectively. The improved rheological behavior and shape fidelity make PEG-functionalized SMP composites promising candidates for 3D printing and other processing methods. These findings contribute to the development of advanced stimuli-responsive materials with tunable properties for various applications, including soft robotics, and biomedical devices.