Development of Shape Memory Polylactic Acid/Ethylene-Butyl Acrylate-Maleic Anhydride (PLA/EBA-MAH) Blends for 4D Printing Applications

This study investigates the feasibility of producing filaments and 4D printed parts with shape memory properties using Polylactic Acid/Ethylene-Butyl Acrylate-Maleic Anhydride (PLA/EBA-MAH) blends. The blends were melt blended and characterized using various techniques, including Fourier Transform Infrared Spectroscopy (FTIR) to analyze chemical interactions, Scanning Electron Microscopy (SEM) to study morphology, and Rheological analysis for viscoelastic behavior assessment. Dynamic Mechanical Analysis (DMA) was conducted to evaluate mechanical properties and glass transition temperature. The PLA/EBA-MAH 50/50 blend exhibited a co-continuous morphology, and storage modulus and viscosity decreased with increasing EBA-MAH content, emphasizing the enhanced processability of these compositions. In 4D printing experiments, the filaments demonstrated successful extrusion and shape memory activation. The 4D printed parts exhibited shape recovery in a rheometer, showcasing remarkable memory retention upon deformation. This achievement is noteworthy, as the majority of the literature focuses on shape memory activation solely in water for hydrophilic polymers. The successful production of filaments and 4D printed parts with shape memory properties at a high filling density (100%) and an orientation of approximately 45° further extends their potential in diverse applications, particularly for flexible filaments with shape memory capabilities. Overall, this research not only demonstrates the successful production of filaments and 4D printed structures but also highlights the impressive shape memory behavior of PLA/EBA-MAH blends. The combination of favorable rheological properties and shape memory activation expands the potential of these blends for applications requiring flexible and shape-shifting materials.