Effect of Low-Temperature Pyrolysis on the Properties of Jute Fiber-Reinforced Acetylated Softwood Kraft Lignin-Based Thermoplastic Polyurethane

Short jute fiber-reinforced acetylated lignin-based thermoplastic polyurethane (JF reinforced ASKLTPU) was prepared and characterized as a short-fiber-reinforced elastomer with carbon-neutrality and biodegradability. The acetylated softwood kraft lignin-based thermoplastic polyurethane (ASKLTPU) was prepared with polyethylene glycol (PEG) as a soft segment. Short jute fiber was modified using low-temperature pyrolysis up to the temperatures of 200, 250, and 300 °C in order to remove non-cellulosic compounds of jute fibers for enhancing interfacial bonding and reducing hydrophilicity with the ASKLTPU matrix. JF-reinforced ASKLTPUs with fiber content from 5 to 30 wt % were prepared using a melt mixing method followed by hot-press molding at 160 °C. The JF-reinforced ASKLTPUs were characterized for their mechanical properties, dynamic mechanical properties, thermal transition behavior, thermal stability, water absorption, and fungal degradability. The increased interfacial bonding between JF and ASKLTPU using low-temperature pyrolysis was observed using scanning electron microscopy (SEM) and also proved via interfacial shear strength measured using a single-fiber pull-out test. The mechanical properties, thermal properties, and water absorption aspects of JF-reinforced ASKLTPU were affected by increased interfacial bonding and reduced hydrophilicity from low-temperature pyrolysis. In the case of the degradation test, the PEG component of ASKLPTU matrix highly affects degradation and deterioration.