The Polymer Society of Korea

Abstract

As demand for multi-functionality and recyclability grows in advanced manufacturing and soft robotics, closed-loop 4D printable polymer systems are gaining attention. We present a sustainable 4D printing strategy using sulfur-rich composites derived from industrial waste sulfur. Tailored poly(phenylene polysulfide) networks (PSNs) and their magnetic composites with Fe₃O₄ or CrO₂ enable hot-melt extrusion through dynamic S–S bond exchange and shear-thinning behavior. The printed structures allow modular assembly, shape-morphing, and recyclability. Notably, PSN–CrO₂ composites exhibit light-tunable magnetic behavior via Curie transition-based demagnetization under NIR irradiation. Using these materials, we built autonomous soft robotic systems with light- and magnetically controlled locomotion, and an MPSN-based stirring bar for on-demand catalyst release. This work highlights the promise of sulfur-based composites for intelligent soft systems.