4D printing of PLA/PCL composites with tunable shape memory properties via printing and programming parameters

Abstract

4D printing of biocompatible shape memory polymer materials is of great significance in the biomedical field. The addition of PCL material into PLA matrix is capable of modulating the elastic modulus of the material while remaining a reduced degradation rate. However, the influence of 4D printing parameters and shape programming parameters on their shape memory properties had not been systematically investigated. Here, we examine the effects of 4D printing process parameters and shape programming parameters on the shape memory properties of PLA/PCL composites. We first explore the effects of key printing parameters on the print quality and shape memory properties of pure PLA materials, and select composites with a PCL mass fraction of 15% to fully characterize their thermodynamic properties. The effects of programming stress and programming temperature on the shape memory properties of the PCL15 composites are analyzed. Finally, the artificial neural network algorithm is employed to optimize its programming parameters, and brings 5.76% enhancement of shape recovery ratio compared with that before optimization. This work provides a systematic study of the shape memory properties of 4D printed PLA/PCL composites, paving the way for promoting their application in the biomedical industry.