Poly(ethylene terephthalate) glycol/carbon black composites for 4D printing

Abstract

This research introduces PETG-CB (poly(ethylene terephthalate) glycol modified with carbon black) composites, a new class of shape memory polymers 4D printed using the Fused Deposition Modeling (FDM) method. Nanocomposites with varying concentrations of CB (0.5 %, 1 %, and 3 % by weight) are developed to enhance the functional performance of PETG in 4D printing applications. Comprehensive characterization at the micro- and macro-scale, including dynamic thermal mechanical analysis (DMTA), scanning electron microscopy (SEM), and mechanical testing, is employed to assess the viscoelastic behavior, microstructural integrity, and mechanical strength under thermal stimulation. Experimental results reveal that CB addition significantly alters the glass transition temperature and improves mechanical properties, with the 1 % CB composite demonstrating optimal tensile strength and enhanced shape memory effects. SEM analysis confirms a uniform distribution of CB particles, contributing to the improved mechanical properties and printability of the nanocomposites. The shape memory tests show excellent recovery rates above 97 %, with faster recovery observed in composites with higher CB content. These findings highlight the potential of PETG-CB composites in applications requiring rapid response and high mechanical performance, making them promising materials for future advancements in the 4D printing technology.