4D Printing of Polyvinyl Chloride (PVC): A Detailed Analysis of Microstructure, Programming, and Shape Memory Performance

Abstract

AbstractIn this research, polyvinyl chloride (PVC) with excellent shape‐memory effects is 4D printed via fused deposition modeling (FDM) technology. An experimental procedure for successful 3D printing of lab‐made filament from PVC granules is introduced. Macro‐ and microstructural features of 3D printed PVC are investigated by means of wide‐angle X‐ray scattering (WAXS), differential scanning calorimetry (DSC), and dynamic mechanical thermal analysis (DMTA) techniques. A promising shape‐memory feature of PVC is hypothesized from the presence of small close imperfect thermodynamically stable crystallites as physical crosslinks, which are further reinforced by mesomorphs and possibly molecular entanglement. A detailed analysis of shape fixity and shape recovery performance of 3D printed PVC is carried out considering three programming scenarios of cold (Tg −45 °C), warm (Tg −15 °C), and hot (Tg +15 °C) and two load holding times of 0 s, and 600 s under three‐point bending and compression modes. Extensive insightful discussions are presented, and in conclusion, shape‐memory effects are promising,ranging from 83.24% to 100%. Due to the absence of similar results in the specialized literature, this paper is likely to fill a gap in the state‐of‐the‐art shape‐memory materials library for 4D printing, and provide pertinent results that are instrumental in the 3D printing of shape‐memory PVC‐based structures.