Sustainable jute fiber‐reinforced auxetic composites with both in‐plane and out‐of‐plane auxetic behaviors

Abstract Energy‐absorbing auxetic composites show flexibility in usage, yet they remain non‐biodegradable, thus creating environmental challenges. Implementing sustainable auxetic materials constructed from natural fibers and biodegradable polymers remains essential for lowering environmental effects. This research involves the fabrication of eco‐friendly auxetic composite using jute and jute‐viscose nonwovens. Scanning electron microscopy and optical microscopy revealed the out‐of‐plane auxetic effect that heat compression produced at different temperatures and pressure levels. The combination of 150°C and 50 psi pressure resulted in out‐of‐plane Poisson's ratios (PR) of −2.6 and −3.0 for jute and jute‐viscose nonwovens. The incorporation of 40% biodegradable polylactic acid (PLA) into the jute and jute‐viscose nonwovens increased auxeticity to −4.5 and −5.0, respectively. Needle punching density controlled the in‐plane auxetic properties, where jute/PLA composites achieved a PR of −0.45, and jute‐viscose/PLA composites achieved a PR of −0.65. The unprocessed nonwoven materials displayed the highest tensile strength of 0.16 MPa for jute and 0.76 MPa for jute‐viscose, but heat treatment diminished this strength level. PLA reinforcement improved composite strength. This study introduces a durable method for designing auxetic materials that can find uses in energy‐absorbing systems as well as protective equipment. Highlights Evaluating the in‐plane and out‐of‐plane auxetic behavior in needle‐punched jute and jute‐viscose nonwovens. Studying the effect of various temperatures and pressures on the out‐of‐plane auxetic behavior of nonwovens. Fabricating a sustainable composite by reinforcing PLA and examining auxeticity. Temperature and pressure have significant effects on auxetic behavior. Optimizing PLA content further helps in improving auxetic behavior and strength properties.